Chappy, any update and/or solution to problem? I have the 7FGCU25 and just started having the same EXACT issue.

Ive cleaned the propane filter
Ran some seafoam through it
Disassembled the Regulator (Didnt find any problems)

Odd thing when it starts to miss, I can spray carb cleaner in and she runs fine for a bit (didn't try it with a load).
I have a new distributor set coming to try.

Any insight would be great as I'm just throwing parts at it now...