I have Riffles book on the M12 but not the Middas book. One of the guns I wish I had back was a M12 28ga grade 5 skeet with a solid rib. I also had a matching M42. Some are kept some are tarded and some will always be missed...those two are missed
I trade a Win 101 Pigeon grade 3 bbl set (20,28,410) for the M12 and M42 but can't remember for the life of me what those were traded for...probably a Parker.