[Welsh Anorak]

As far as I remember these were made by Orion who supplied badged sets to Currys and Dixons. They were pretty good with few serious faults. As you suggest, the cleaner one probably has dry joints, and I'd resolder the line driver transformer's connections first as that was a weak spot on Orion TVs of that era.
As they are getting on now, it's worth checking the wedges that hold the scan coils in place. The silicone used to fix these on 14" Orion tubes used to rot the coils. You can see a big white blob of adhesive on your fourth picture. You can carefully remove the wedges and clean the area if necessary and reattach with a non-acetic silicone. Hopefully you won't need to.