Which cantilever to choose for re-tip

By the way, I am only quoting the advice of Jonathan Carr, who designs Lyra cartridges for a living.  He also pointed out that there is a significant difference in mass between boron and sapphire, which would have led the original designer to choose different materials for suspension and damping of boron vs sapphire, etc.

Shelter makes great sounding cartridges; I just wish they had a rebuild, retip, or at least an exchange service - but I've never heard any examples of such a thing? 

What's a shame is that a brand new 501 Mk III costs only like $1000 or so from Japan, right? The $450 boron retip would get you back a Mk II at best, and that's close to the 50% cost of a newer Mk III that you'd expect to get back from a rebuild service (if Shelter had one price-structured like Ortofon and Koetsu). And of course the ruby cantilever will definitely change the sound, maybe not for the better. I don't like either of those options. I'd probably try to see if another retipper can keep boron for less money, or I'd get what I can for the 501 as-is by hocking it, and then buy a brand new Mk III from Japan.

Stick with the Boron.

Ok. Seems boron is the way to go on the Shelter. More than half what I paid for the cartridge but still seems worth it if it sounds great when repaired.
I decided to have them evaluate the Lyra. The stylus looks fine but has turned sideways. The cantilever is loose. I hope they can glue it.

FWIW, I chose boron for my Benz Ebony LO, which is what it came with, and I'm very pleased. Sounds like stock, which is what I wanted.