Dunlop Special Lightweight rims, as has already been mentioned, are definitely worth saving. They were made from the late 30's until the early 60's, usually in either 32 or 40 H drillings. The chrome is excellent, and they really are lightweight --similar to aluminum. I understand they were also made in stainless steel, though I have never encountered that.
I've got one stainless Special Lightweight and one stainless Endrick. I think both are 36 holes.