The 24 is an entry-level, low powered springer. By entry-level, I mean a beginner's rifle, not a toy or cheap gun. The 25 is, as far as I can tell, an upgraded 24. The 27 is the old mid-powered gun which was made in several variations from the 1920's until the late 70's or so. The more recent guns are quite popular, being comfortable to shoot and accurate with a good trigger. Not overly heavy, either. The 35 was the more powerful springer and maybe about 100 fps faster than the 27. Also a nicely balanced gun, although no longer considered "powerful" by today's magnumitis crowd. Winchester imported these in the late 60's/early 70's and those models sported a bit nicer stocks, the Winchester logo and series numbers based on Diana's with a "4" added (425, 427, 435).
Search on the Vintage forum for more info or try here:
https://store.bluebookinc.com/InstantAccess/Model.aspx?product=4&id=91