Help needed- Replacing crystal on GF/ORF NTTD

[maplesirup]

I purchased a GF/ORF NTTDand do really like the watch. But the incorrect magnification on the xtal bothers me- as well as the Lack of proper AR but thats a different story..

Does anyone know how to source an aftermarket xtal? Maybe someone has some experience in this matter for the NTTD?
your Input is highly appreciated.
cheers