I once made some objects(basically recolors of Maxis ones but cheaper because I wanted starter furniture) and uploaded at TSR. Of course I had Magic Cookie and wrote them down, but over the years you know, upgrade to newer machine and so on, I 'lost' it. Retrieving it from objects seems to be the only way unless I dig into old HDDs. Then today...

Found old TSR archive, downloaded 2GB of object files, extract them, search for certain string from their names I remembered, extract two of the results to \Download, open them at IFF Pencil 2, get GUID.... I got it.
Mine is 13310(0x33FE). I doubt if I'd do anything with that(like making new object), but if anyone use 78846(0x133FE), they can conflict with any of my old works(dunno if anyone would use them), just let you know.