I'd keep the cottered crank. Campagnolo derailers wouldn't be my first choice. I'd go with either metal Simplex or Suntour V.

Try a set of Tufo Tubulars applied with Tufo tape. Don't use the sealant until you get a flat. It will dry out inside the tire. That's how I do it, but I've never had a flat. I just carry the sealant and a valve tool.