Yes it's all sorted now, im didn't update the thread on here as there was no interest.
There was one too many shims on the rear sled which was preventing it locking in the forward position. All now sorted and shooting perfectly
Of another forum.
Well after a long wait my, feinwerkbau grease finally arrived from Canada. I had already recived my maccari seals and spring front he USA.
While in bits I oiled the grips and using an airbush touched up some of the worn parts on the frame.
The seals were a perfect fit but the spring far too long, the pistol wouldn't cock with it in and I had a hell of a time getting it in the action. I think cut to the same length of the original it would be ok, something I'll try at a later date.
Using a small amount of the fwb special grease (which doesn't combust) I lightly lubed the comp tube inside and outside.
Once reassembled and with the correct shins on the recoil sledge it now shooting spot on.
Maccari seal set
Showing the piston ring seal
The machining tolerances are superb