+ Shimano and Campagnolo alloy rear hub carriers.
The 14 hole x2 hub + mounted Campy cassette carrier weigh about 200 grams.
The bearings should all be replaced, Bearings are the same for most, if not all Zipp 202 303 404 808 products, and can be sourced for between $2-$10 a piece.
There are signs the hub was mounted to a wheel on the cassette side, and then uninstalled The unmounted Shimano freehub has a slight wear line at the 13 tooth cog on the cassette hub, but there are no cog hub notches on either free hub anywhere. There are finish stains but no signs of use on the attached Campagnolo freewheel hub. I haven't tried to remove stains with solvent because parts are probably clear coated or anodized finishes.
I easily mounted and removed a 9 speed DA 7700 cassette on the Shimano free hub. I don't have a Campy cassette, but the Campy freehub is 36mm wide to the lock ring, so it should accept a 10 spd cassette, and there are aftermarket 11 spd cassettes that have been adapted to work.