I think the one on freeads now might be the same one that was advertised on the BBS a year or two ago and has subsequently been refinished, before resale.
It had previously also been bought off freeads, before being advertised on the BBS and had a scope rail fitted and removed. If you look at the pic of the current sale, it has a flatted area on the top of the cylinder where the base was.
Might be mistaken though.
Might be something to do with this chap, but not certain