[Tim]

Had it running for 12 hours the other day, and once warmed up the timebase is spot on(well within accuracy possible due to thicknesses of lines and guesstimating scales, inherent parallax etc.) with various frequencies checked with a frequency counter. Y volts div is about two small divisions out on every range on both channels. Both channels are the same though, and the same wave applied to both Y channels simultaneously fit over each other perfectly.
So just some tweeking needed really.
Unfortunately I do have severe distortion on one part of the screen, which I think may perhaps damage or something inside the CRT. if you arrange the trace to miss it the rest is fine.