CT100 sapphire crystal - Where can I find one?

Hi, I have a Citizen NY0040-17 that I would like to get serviced and while it's in the shop want to get the old scratched mineral crystal changed out for a nice sapphire double dome.

I have contacted the watch maker and he cannot source a non genuine part (apparently 🤷‍♂️) but is happy to replace it if I can provide one.

Trouble is I can't seem to find one of these crystals anywhere and everywhere I do find one listed they are out of stock.

Can anyone offer a suggestion where I may be able to pick one up from?

TIA