According to some 1940's, 50's and 60's catalogs, Logan used the same model number for their 10", 11" and 12" bed turrets. As they obviously can't all be exactly the same, there must be at least one (and could be more) part that is size specific. We just don't know what the part(s) is. AFAIK or recall, we don't have a parts list/drawing for any of them. It wouldn't hurt if someone who has one of them were to call, email, etc. Logan and ask for a parts manual and also what part(s) is different. And then put, or send the file and other info to me and I'll put, everything into Downloads for everyone else.