I recently bought a 1983 Peugeot P19 mixte and was abruptly and unceremoniously introduced to the world of Simplex derailleurs. Being a grad student on a tight budget I played amateur bike mechanic and spent 2 hours trying to figure out what was causing the weird clicking sound, like the chain was catching on something in the derailleur. After standing behind the rear wheel I suddenly saw it--3 missing teeth on the plastic jockey wheel like a rat had gnawed it off. Yikes!

Luckily for my student budget there's a bunch of YouTube videos on how to replace the gears in a derailleur. I was looking at a vintage derailleur conversion kit on eBay:

https://goo.gl/pvW8HR

Would this kit work for a Simplex SX610T derailleur?