I think I know of the eBay lot your talking about.....
To be honest I was just trying to source one set of the bolter arms, I saw last month the three sets on eBay and put about £10 on each set, hpoing I'd win at least one of the sets so I could get my hands on the Bolter arms....
You see I have several sprues and loose figures already with all the heavy weapons and close combat pistols, but I didn't have the bolter arms to finish repairing my figures....
If I can just get one set of those bolter arms I can make a mould and recast them for my personal use, to use on the 10 Strike Force metal marines they put out in 1990, you see, those first metal mk7 marines had arm sockets which the RTB01 arms fitted onto....