In response to the suggestions and a few hours fettling, I think I have something... It's a bit rough around the edges in places, but it's my first one and I'm quite pleased with it.
The resolene has come off in two places, but has made it look quite tacky IMO. I've looked at restoring leather to try remove the finish and start again to which I found people mentioning IPS and deglazer. I got both just to be sure. I'll always use the
IPS on electronics and the like.
I had a bit of a struggle getting the cheek piece and tension right. It wasn't until I'd I thought I'd overestimated when I realised that I'd REALLY underestimated! Anyhow, we got there in the end. As you can see in the photo's, I've used a bit of everyone's ideas, so thank you all very much for your time and knowledge.