Hmm, dont know if this is true for the Maple Leafs, but take a look at this tech tip:

http://www.stovebolt.com/techtips/series.htm

Also these 2 pages, from Jim Carters Catalog:

http://www.oldchevytrucks.biz/47_55/t1.asp?page=6


Hope this helps! I dont think number designations were given till halfway between the advance design series, the year in one of those links, I've seen it before, but dont have time to do a search though them now. Sorry, but I think this should at least get you started.


No 'bolt yet, but if you'd like to help me out with that, send me a message! Or check out my wanted add in the swap meet.