I am holding the firearm right now. It has the low front sight like the regular rifle but a ventalated shroud like the LMG. It feeds from the left side via the same box mags as the LMGs. Verbage on top simply says: Ejercito Mexicano Serial Number 0005X and on the right side of the receiver it says: Systema Johnson Model 1941 Calibre 7mm (in a light inlet where something was obviously milled down a bit) Fabrica de Armas Providence, RI USA Selector says: SAFE (12 0'Clock position) FIRE (3 0'Clock Position) Some of the other Johnson LMG pieces I have DID come from the Winchester Museum so your guess is a distinct possibility. My records indicate that it is "a Mexican issued Johnson model of 1941 Semi-auto millitary issue repeating service rifle - Experimental model: cross between Model 1941 Semi-auto rifle and 1941 light machine gun" but I want to verify this. Thanks again! Jeff Z