The guide pulley usually has a wider busing than the pulley itself which alloys for it to move from side to side, this allows for imperfections in cable tension and a quieter drivetrain. At least that is the way all shimano SIS derailleurs are made. In my experience 8s shimano pulleys are a good sub for old campagnolo as the bolt is the same diameter. I recall the older suntour stuff being a larger diameter. Who knows; you could start mixing and matching pulleys and bushings.

I don't see how the pulleys repechage was sold in the nuovo records could not spin unless there was a bushing and dust cover mis-match. The pulley dust caps are meant to fit tightly against the bushing so it does not move and the pulley spins around it. There are deep and shallow lipped covers and I suspect the seller did not have the matching covers or the wrong busing.

The non-record campagnolo pulleys tend to be similar enough, but did not say campagnolo on them. I have a few spares. I also have a few record pulleys that are split on the seam. I think some people have super glued them, but I haven't bothered trying yet. I also note that there was a change in Nuovo Record pulleys at some point. I seem to recall there being a brass sleeve on the earlier ones and later that may have disappeared. Once again though, it has been to long since I looked.