Adapter needed for field flattener

[chouet]

Hi all

I have a WO FLT110 (the TMB version). I've now acquired a Field Flattener  IV which is 0.8x rather than the TMB 1x. However, I have a Feathertouch focuser so the standard FF IV adapter doesn't work. I've tried using the 2 inch nosepiece, but I don't have enough inward focus travel so need to shorten the back focus.

The thread on the feather touch / TMB appears to be 92mm and the FF IV 50mm/2 in. So, I think I need an adapter which is 92mm male to 50mm male. Any ideas?

Thanks!