Several ways to spot a fake 28 gauge Model 12. First, ask the seller to remove the buttstock, the original factory gauge stamping will be found on the rear boss of the receiver. The 28 gauge M12's were built on the same frame as the 20 and 16 gauge M12's. Then look at the forward magazine loop hanger. the original 28 gauge will be stamped 28 on the rear left (left side of the receiver, opposite the right side ejection port- also, if you know metallurgy, that part on an original factory 28 gauge will be blued forged and machined steel, not the post 1964 investment cast hanger- and finally, the extractor on the 28 gauge is different in shape at hook than the one found on the 16 and 20 gauge M12's- but you have to know how to remove it from the bolt, and what to look for.
There are more crooked gun hustlers extant on the 28 gauge M12's- none on the Model 42's, so perhaps those are a better investment. Saw a 28 gauge skeet with a factory Cutts and solid rib for sale at Cabela's the other day-- 50% wood finish and checkering, 65% blue- asking price is $11,500 and there are no extra choke tubes or choke tube wrench included. They also have a field grade M21 20 gauge 28" barrels with a matching set of 30" 28 gauge barrels- straight handed grip, Silvers orange pad, Kidney shaped beavertail forearm, 95% blue and wood- $16,750.
