Anyone have an idea on a crystal for a front loader Wyler

[RLang386]

This is one of my newest ones, a Wyler automatic, not sure as to the date but I was guessing late 40's early 50's. 

It's a front loader, you pull the crown of and then remove the bezel, the crystal has a rim which is retained by the bezel, and then there's a thin movement ring that wedges in between the dial and the case. Crystal is shot but it runs well. Someone loved this watch, had it serviced, is my guess. 

Any idea on where I might find this kind of crystal? The odd thing is it's definitely plastic, so it's got to be a replacement from later, right? 

I can't for the life of me find my micrometer but I will later and provide any measurements needed. 

The markings say (or said) Wyler Incaflex and Automatic. Caseback says 185956 if that helps.