Hmm....is it possible to see the difference between a Henry and Winchester in 28mm 
I'd say it would be possible to tell the difference in any scale, but then I do own and shoot both, and I'm a bit of a vintage firearms anorak

The Henry loads down the tubular magazine, whereas Winchesters load through the side-gate (which Henrys don't have). Winchesters have a wooden fore-end, Henrys have none.
The Henry's barrel length at 24" is the same as the 1873 Winchester rifle, but is indeed longer than Winchester carbines, which have barrels usually 16-18" long.
The figures shown appear to have firearms representing the carbines, as these usually have a barrel band around the fore-end, the W rifles Henrys did not, so conversion of these would also involve filing away the barrel band.
Conversions from Winchester types to Henry are a bit of a faff but can be done: cut away the fore end and magazine tube, replace the magazine tube,fill in the side-gate etc., there's more to it than that really, but that'll about do it

One more point which can be overlooked in 28mm, is that Henry and most Winchester rifles had octogonal barrels, those of the Winchester carbines tended to be round.
I know, I know, but I admitted to the anorak
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