Hmm. Not having bothered to do any actual research on this myself, how did the Irish Army infantry look at that point in time? Much different then the Jadotville 10 years or so earlier?
Quite a bit, the Emerald Isle being somewhat less sunny and warm than the Congo.
For the regulars in the late'60s through to the mid 1970s, the look is basically British Army 1960 pattern combat dress with mostly '37 pattern webbing, toting FALs and the odd Swedish K submachinegun.
Differences with the British Army are relatively subtle at this point as the British Army was also still in 1960s combats for the most part, with the 1969 pattern DPM stuff just coming in to service. Obviously Irish rank slides are markedly different but other distinguishing factors include high black comabt boots (no puttees as per the Brits) and the FALs being uniformally wood buttstock and plastic/metal forestock types.
The Irish Army also used Mark 5 turtle helmets and they tended to be unadorned or at best covered in a net, rather than the fully cammed up tin hats you would see on the British Army outside of an urban context. I've also seen photos of the odd Armoured Corps steel helmet (same shape, different suspension system as the better known para pudding bowl HSAT) mixed in with the Mark 5s.
In the absence of figures (at this point) in combats with '37 pattern webbing, the best figures for an early 1970s Irish Army would be the Wargames Atlantic SAS/Commandos, who are wearing very un-windproof smocks but look a lot like 1960s combats. Add the Empress unadorned steel helmets (available separately) and source some FALs and you'll have a decent approximation. As so many of the WA figures are toting Thompsons or Brens, these woud be the easiest way to convert to pistol gripped rifles.
The other alternative would be Warlord British paras with the crotch flap filed off but these represent a lot more work. I know, I've tried. 1960s combats lacked the thigh pocket on the right leg, so just file that off if you want to be anal about it.
As the 1970s progress, you get increasing use of British '58 pattern webbing, typically without the respirator pouch. The battalions sent to the border tend to be in pretty much the same flak jackets as their counterpoints north of the border for patrolling but woud have likely ditched them on a general war footing as fighting order is not a comfortable or practical fit with M-1969 body armour. You can essentially use British Army figures (Empress, Crooked Dice, 1st Corps etc) for the Irish in the mid 70s to early 1980s. Just file off the puttees and paint the boots solid black. At least one figure per section need to be converted to carry a Swedish K but that's about it. There are the bare metal Empress heads if you want to show an identifiable difference.
By the mid 1980s the Irish Army are still in (slightly modified, locally made) green combats but are wearing Israeli Orlite helmets. Troops photographed on the border still wearing M-1969 flak jackets.
The Irish army reserves, the FCA, are pure WW2 at this point and remain largely so up until the end of the 1980s. Bulls wool jackets, WW1 era tin hats (if any) and they were still equipped with British Mk4 bolt action rifles and Bren guns both in .303 but again with the Swedish K for their NCOs. You'd be best off using WW2 British army in battledress.
In the later 1970s and 1980s many FCA members started to privately purchase combats , British, ex-Irish army and even the odd more exotic item from Europe or the US, so long as it was basically green. I understand that US M-1965 jacksts were quite popular. If, for some utterly quixotic reason, you wanted to model the 1980s FCA, you coud probably just use the 1st Corps Korean War Brits.
Now, the panoply of armour and guns is truly weird/ impressive. The Irish Army had a wonderful mix of 25 pounders and 4.5 " howitzers as its artillery park. The 4.5" were the pre-WW2 Parry conversions (pneumatic suspension) but the guns themselves date back to before the Great War. Toss in a handful of Bofors guns for anti-air defence of vital assets. They also had an interesting collection of French 120mm mortars to bolster their arsenal.
Armour, at the turn of the decade, was truly eclectic. The Irish Army had only just ditched the last of its handful of Churchill tanks a year or so before. There was a handful of similar vintage Comet tanks, for which the Irish army had largely failed to buy spares and whose HE rounds had been dropped due to unsafe fusing issues. One of the Comets suffered a turret fire in the 1960s and so they removed the turret and replaced it with a Bofors 90mm RCL on a ring race. Now there's a fun modelling challenge.
The armoured might of the Republic wasn't confined to tracked vehicles though. Still on strength until 1972 were the 1930s era Landsverks and Leylands and even then they weren't retired just passed down to the reserves, who at this time still had those fabulously Heath-Robinson Ford Mk VI armoured cars of Congo fame/infamy.
Meanwhile the Irish government had found some cash down the back of the sofa and in 1964 purchased a batch of Panhard AML-60s. These were primarily intended for peace keeping duties (Ireland was a contributor to the UN presence in Cyprus at the time and later would send battalions to Lebanon for decades to come) the surplus equipped cavalry squadrons in Ireland, alongside then supplanting the miscellany of ancient shite in service. They ordered some more in 1970 including the 90mm armed gun version and these would all be in place by the mid 1970s.
They would also order and receive the M3 APC version of the Panhard around the same time. These were very active in border operations from the late 1970s onwards, each infantry battalion along with the cav sqadrons getting a handful for patrolling purposes.
By the 1980s the Irish military behemoth had reached peak military power projection, having added Scorpion light tanks, a few Irish-Belgian APCs of dubious worth and some even more dubious scout cars based on a Unimog chassis, purchased second hand, that would roll in mild breeze. The skies woud be kept free of would be raiders by a handful of Fouga Magisters (replacing similar numbers of doubty Vampire trainers ) and bolstered in the ground attack role by the devastating fury of SIAI-Marchetti turbo prop trainers. The world trembled and neither the Warsaw Pact or Britain challenged Ireland's armed might.
Almost none of this would feature in the Jack Lynch goes bonkers scenario but the Irish Army was tasked later in the decade with reviewing options for intervention if the British Army was withdrawn from Ulster.
What I like about the period is that the Irish Defence force is almost the perfect post war 'Imagination' or
AK-47 style nation. A developing country with a truly eclectic mix of modern and ancient hand me downs.