There were 4 main M1 garand bayonet types. The first type is the 16in aka long bayonets. I think these were discontinued around 1942 or 1943 in favor of 10 in versions. For the 10in versions, some were made as 10 in bayonets and others were cut down from unissued 16in bayonets. The cut ones will have the blood groove aka fuller go all the way up the blade where as the "m1 bayonet" (I don't know the exact name) will have the blood groove stop, as pictured below and as pictured by the OP. The 4th type is the Korean war m5 type, which had the M4 bayonet (for m1 carbine) blade. That blade type was also shared by the m3 fighting knife, the m6 bayonet for the m14, and of course the m7 bayonet for the M16.
Winchester never made any garand bayonets. I know Winchester made P17 aka 30-06 Enfield bayonets (I had one - these also fit the 1897 Winchester trenchguns) and I think they made bayonets for the Russian contract model 1895 Winchesters. M1 garand bayonet makers included but are not limited to: Pal, AFH (American For and Hoe), Utica, UFH ( Union Fork and Hoe), OL (Oneida Limited), and WT (Wild Drop Forge and Tool)
