I gotta concur with the last two postings. Any B&W tube TV, especially a low B+, minimalist design, is gonna have very fluid parameters in its performance, like tubes and components aging, low and/or fluctuating line voltage etc. The design has built-in 'headroom' to allow for this. And very few sets if any will display perfect linearity, either horiz or vertically. Even If you set everything as near 'perfect' as possible, it's gonna change on its own.
The results you've already attained with this project have knocked everybody's socks off, and achieved performance beyond any typical BW set of the period.
(Edit) There's an old adage relating to model aircraft design, but it applies here as well: "Perfectionism is the manic form of fuddyduddy-ism."
I would be 110% happy with what you have there now.