Elbows, I haven't re-based the fences at all. All I've done is to give 4Ground's bases a coat of PVA and sand, but prior to attaching the boarding on the rails.
I'm still not sure about MDF kits where the tabs really show. But these 4Ground houses are so cunningly designed that they don't need visible tabs, except for a couple of places on the verandah roofs (hidden by the thatch, though) and on the ridge-pole structure on the roof (which I could easily disguise with some paint).