Very informative, thank you! I have things closer yet, but not still not great. Best result, with no underscan even, seems to be with the yoke mostly pulled back. Everything goes way out of whack when moved forward. I'll aim to get hold of a degauss coil before really beating myself up on this further.
Side note- the purity ring/blue lateral magnet setup on this set is so weird, rings are inconveniently behind the magnet, very hard to get hands on. I'm about 99% sure it's not on backwards either. The magnet adjuster faces forward.
