soldering silver ring with sapphire in place?

[camalidesign]

Hi guys,

Hoping for some pointers/advice. I have a green smooth sapphire cab set into a simple silver ring (part of a stacking set, pictured), but I have a customer who loves this stone and needs it to be 3 sizes smaller...

Firstly, does anyone know of anyone that would be able to supply me a stone like this? It's a 6mm smooth green sapphire, not quite as vibrant as in the picture, but still a nice bright green. The supplier I got it from don't have any more in stock.

Alternatively, I should be OK to just cut the shank, immerse the setting in thermo paste and solder it shut again? Any tips/ideas?

Cheers,
Carin