Tamron invented the T-Mount !
Something more to read.
http://en.wikipedia.org/wiki/Tamron
I have often seen eBay listings for various Tamron Adaptall adapters - usually between $10-30 , just a matter of finding one for your camera.
If the lens is the early series then its probably a T Mount - so you need a Canon to T-mount.
I bought about 20 Adaptalls for $20 as surplus photographic junk from a camera shop recently but nothing for Canon.
Cheers Rally