I presume if you didn't get a reply it was because no one here really knew the answer to your question. I assume you wanted facts, not conjecture.

As to quill stems with 26 mm bar clamps, those should still be common and I further expect your quill diameter is 22.2 mm which is very common on all but older French and a few other bikes like old Schwinns. Here is one US source:

http://www.jensonusa.com/store/produ...inum+Stem.aspx

Here is another: http://www.lickbike.com/productpage....B='1173-10'