Source for replacement window? - Rear of TAG Grand Carrera

[gorilla1969]

I have a TAG rep Grand Carrera Calibre (bought from Angus) which had one of its rear 'half-moon' windows in the rear cracked (one of two windows that shows the crystal/movement inside the watch). It cracked inward and stopped the movement. I removed the cracked glass and got the watch keeping time again. However, I need a new window to keep the inside from gathering contaminants. The old window appeared to be attached with a self-adhesive film around the edges.

Is there a source where I can buy a drop-in window to replace the old one?

Much appreciated!