Want to Buy WTB: Graflex/Singer RH8 6x9 Film Back

I'm looking for a nice condition working Graflex/Singer RH8 6x9 back. Not the 4x5 version. As long as the spacing is fine and advance is smooth ( basically working order ), and the dark slide. I'd prefer the one with the lever but the knob winder is fine too. I'm in US.

Thanks,

Bill