Ralph is offering a neat little doo-dad on ebay:
These were commonly used on track bikes and were designed to hold the nose of the saddle at a constant height. You attach it to the nose of the saddle (underneath) and around the top tube. You then dial it in to the perfect height and voilà. They really do add quite a bit of pizzazz to your vintage track bike. I have a couple of these myself in my stash but don't want to sell them as I believe they are quite difficult to find.
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Steven Maasland
Moorestown, NJ