Duramix is now a
3M product and any 3M dealer can order it for you if they don't stock it. The 40/40 is a very good adhesive for composite parts and the 40/58 is more of a filler with a little weaker bond, but sands easier according to my guy that paints my cars. I've used the 40/40 to bond and it's very strong, I think stronger than 3M's regular structural adhesive.
I wasn't aware they had it available in smaller quantities, I've always used the double tubes in the special gun.
John Stricker
Edited to add, the guns are about $100, the adhesive is about $45/tube. (at least around here, over the counter)
[This message has been edited by jstricker (edited 11-20-2004).]