I have been looking around and see a campagnolo freewheel tool kit, which looks to have a thread on freewheel in it. But am unable to find an actual threaded freewheel by campy its self.
I have a Campy alloy 6 speed freewheel on my Rock Lobster. It was made in the late 80's and cost $325 back then. Keep an eye on eBay or CraigsList, they do show up from time to time. You'll also need the Campy specific freewheel puller to get it off.
The only parts that I don't recall Campy making are bars, stems, saddles & tires/tubes.
Oh, and possibly chains & spokes.
My Lobster (#13, built long ago, back in the shire) is all Campy except;
Bars = Cinelli
Stem = Cinelli
Saddle = Avocet III
Tires = Vittoria tubulars
Chain = Regina hollow pin
Spokes = DT double butted w/alloy nipples
Toe clip straps = Alfredo Binda
was trying to do an all camp build out but i guess there is a limit.
Go with an old Regina freewheel, they're on ebay regularly. They're Italian (the old ones, anyway) and most Campy-equipped bikes came with them during that time period I believe. I found exactly what I was looking for on ebay in a Regina five speed freewheel recently, 14 x 26, grimy looking but it cleaned up beautifully. I paid $9.99 plus shipping. It's going on my Campy-equipped '72 Raleigh International. Original freewheel on the bike was a five speed Regina 14 x 24 I believe, but that was long gone when I got the bike-