Originally Posted by paxtonm
It's got horizontal dropouts. Sooo, is there anything preventing me from removing a bunch of stuff, and going fixed?
No.
Originally Posted by paxtonm
The rear hub now is set up for an old school freewheel. Does that work for a track cog and lock ring?
Works for the cog, but not the lockring. Depends how much of a risk you are willing to take. Loctite + rotafixa torquing are enough for some folks. A lot more would call it a suicide hub.
Originally Posted by paxtonm
Would it be prudent to build a new wheel?
Yes.
Originally Posted by paxtonm
Do old Campy cranks accept track width chainwheels?
Chainrings are available in a variety of widths (chain compatibility) and BCD's (crank compatibility). Yes.
Originally Posted by paxtonm
Also, kinda hilly here. I was thinking 44x17. Is that about right?
Probably. There's no way to know without trying.