What Cartridge Manufacturers Will Retip Their Moving Coil Cartridges For A Fee?

Ortofon rebuilds, at least the higher end models. Only the body is reused, I believe, and the cartridge gets a new serial number. My A90 has been done thrice.

I have two Lyra Atlas Lambda (SL + Mono) and a DV XV-1s. I am happy for them to get a rebuild. I don't see a need to get a whole new cartridge out of it. A rebuild the way Lyra and DV do it is pretty much the same thing anyway. It costs an arm and leg either way. 😉

I think Soundsmith has the best deal for re-tips/rebuilds.  Their top cartridges have great reviews and people do like them - you should be able to find something compatible with your Sumiko. The Hyperion ES Mk II, their top MI cartridge retails for $8k and the rebuild is only $850 to the original owner. That's hard to beat.  

Van den Hul.

Rdk, yes, but, as previously mentioned, SS make MI cartridges. The operating principle is different from that of MCs, making rebuild a much simpler exercise. That’s a real virtue but not what the OP asked.