My RD is a Superpe Pro and my frame has the standard braze-on to hold the end cap piece of the rear derailleur cable. I have noticed that the barrel adjusters on other rear derailleurs, intended for indexing, has a narrow enough threaded section so that I could shove it in the existing frame braze-on, with a little persuasion. This would not be good for the braze-on, and I still would have to put a nut on the barrel adjuster to back it off or advance it into the braze-on. Is there some other way to go to index shifting? I am staying with downtube levers, and I gather they don't come with any adjusters on them. The derailleur itself doesn't look like a good candidate for an adjuster, and I want the period correct derailleur that it has now. I want it all to look classic too. Garth Libre