I finally managed to make some time and got it rebuilt yesterday.

I'd sourced a Welsh Willy kit for it. Had a lovely chat with Will. And the kit arrived just two weeks after ordering rather than the quoted four or five! I'd also asked him to go a coil shorter than usual as I'm not concerned over power and would rather have a sweet shooting medium powered characteristic. But also asked for some extra spacers just in case.

I opted for the Meteor 'O' ring.

There was about 20mm to compress before the end block threads engaged and fitting the end block was very easy by hand.

I only had time to just fire five shots into the pellet trap. Cocking effort very easy and action very smooth. Firing cycle feels lovely. I'll hopefully have a plinking session with it on Sunday and run it over the chrono.