Want to Buy WTB: 8x10 film back for Rittreck View 5x7 camera

I have a Rittreck View 5x7 LF camera and have both the 4x5 back and 5x7 back.
I am looking for an 8x10 adapter film back for the Rittreck.
I would prefer the wooden one but the metal one will do.

Thanks for your help

J