It gets a bit irritating when every newbie introduced to Simplex dropouts refuses to understand them for what they were intended, especially when simply using a basic, non-plastic (read = reliable) Simplex RD is - bar none - the easiest way to make a Simplex dropout work in your favor.

Not only that, one even has a choice between straight or drop parallelogram with Simplex; enough to satisfy both Campagnolo and SunTour fans alike.

Correction. "I," not "we." Don't unnecessarily blame the rest of the forum on account of my own irritability.

-Kurt

P.S.: Come to think of it, if that dropout were tapped, wouldn't a Mavic SSC RD fit with no further modifications? Just a thought - especially as a Mavic SSC will likely run the OP more than a reasonably-priced Simplex SX 610.