I'm thinking of buying this Admiral

[EdKozk2]

MadMan,
After you reverse the ion trap and reset it, you may find an improvement in the focus. Otherwise everything looks good . Some of the horizontal linearity issues and slight phase shift you mention seem to be inherently common with these Admiral sets. The last three Admiral sets I repaired had some of the same issues.
I just got an Admiral 12X12 this past weekend, won't get to it till next year.
Did your set come with a metal rear cover and metal underside shield ?
The rear cover that came with mine looks it may fit more than one model.
Ed