I think there's some confusion between Michigan and Kalamazoo - the latter was used by Gibson from time to time as a trade mark for cheap line instruments. Kalamazoo accoustic guitars are supposed to be very worthwhile (as used by THE Robert Johnson - J shape & black), although the three I have seen in GB were small jazz guitars, fourteen frets, no cutaway, black finish. These all played and sounded good. Others I have heard of were solid electrics with a composition body and bolt-on necks, which were not very good. I believe the Michigan name was used by a 30s mail order company to market instruments made by Framus and Hofner - I've seen it on banjos and banjoleles.