Oh I totally get Steve's point, and it's valid. His experience is valued, and I've read enough of what he has to say about these bikes to know that there aren't many people around who know more about them than he does. I'm never, ever, in favor of "half assing" any job. I am however in favor of a substitute that serves the same function at 1% of the cost.
A guy I am lucky enough to work on bikes with sometimes is an absolute encyclopedia of vintage bike mechanics. He has spent so much time fixing other people's bikes that his answer is always "buy a new one." We were working on the brakes of my Suzuki one time and he looked at some minor pitting in the caliper piston and said "That needs to be replaced, buy a new one." I said "No, new ones are hard to find and very expensive" and his response was "Oh, well then that one will be fine, clean it up and put it back." I relate that story because so often in vintage bikes the answer is "buy a new one" even though there are other options. I try to use my best judgement to discern when there is no substitute for replacing the part. In this instance, I'm going to buy a hardware store washer, grind it down until it looks like the pictures on Google, install it, and see what happens!