Sorry to say thing have moved on the biggest problem is that the chain has gotten narrower and the length of the BB spindle too. You can still get 175 cranks but they now come with 53/39 or a compact 50/34-36 just do a Google search for Campagnolo and the groupo you want now from the top it is Record--Chorus--Centaur--Veloce--Mirage.

What kind of headset is it? I would think it is a threadless (the top has no threads). If so the stem you have will not work.

As for the other thing I would look to buy some new stuff. The handlebars, post, and seat should still work if the money is not there.