I agree that the original B&O cartridges were good sounding, but personally wouldn't consider a re-tipped B&O original cartridge because it probably still has the same 40 year old suspension inside, and that suspension is prone to collapse because of age alone - without any notice. I have an original B&O MMC3 sitting here with a perfectly good low-wear stylus and cantilever, but the suspension is collapsed - which is not an uncommon problem with these. Now if the re-tipper is cutting open the cartridge body and replacing the suspension inside as well as the re-tip then I would certainly consider that. The problem with the old original cartridges as I see it is that the rubber/polymer suspension inside deteriorates with time alone. The re-tipper I spoke with wouldn't touch it because it is too hard to open the body.
I have an SMMC4 now on that B&O TX2 linear tracker and it sounds good because I have a home-built tube RIAA phono stage, with added bass and treble controls after the RIAA EQ. Initially with a regular RIAA-only phono stage it sounded too thin and lightweight to me. This could be a combination of the cartridge and the low mass platter/arm, I'm not sure, but turning up the bass control on the home-built tube phono stage made it sound fine.
the thin end of the wedge