RCA 21T9236 (KCS122E) - Repeating skewed trapezoid image

[AppliedTech]

Greetings, new to TV repair just done a couple tube radios. Guessing here, but this seems like a question about geometry adjustment but may be a symptom of a bad tube or something more seriously wrong.

I'm working on a 1958 RCA 21T9236 (KCS122E) I picked up at an estate sale. The video out/horizontal/vertical tubes were all missing, and the rectifier 5U4G was shattered still in its socket. No marks around flyback and transformer but a pool of wax and melted/blown caps on the video, vertical and horizontal boards and electrolytics were no good. There were signs of a couple repair jobs and caps of all ages, who knows how much fiddling has already been done. Recapping everything non-mica and replacing the missing or broken tubes led to noisy static and a heavily skewed repeating trapezoid image after feeding the antenna through a matching transformer from a converter box. At this point I injected component video and audio to bypass the tuner so now the sound is clean and the trapezoid is still there but was crisp enough to read the title card for "Monty Hall" sideways in the slanted image.

So at this point vertical locks with a wide range of give or take on the knob, but horizontal barely locks into this steeply skewed repeating trapezoid image. Rotating the yoke only made the raster rotate but didn't impact the trapezoid. Reading the copy of SAMs I have for it I'm not sure if this is "poor vertical linearity or foldover" and so maybe I need to replace the vertical tubes, or just don't know how to adjust the geometry. Searching through various forums came across some mention of the wrong tube in use, but have checked them all and their labels match the schematic.

Attached is a picture, would someone be able to help identify what this type of problem is called and what's typically the solution?
Video: https://youtu.be/yGBZgebYuv8

Side note, it is also overshooting the screen size and I need to shrink the width/height. Before getting to that I had to shut it off because there were a couple blue sparks in the tube (overshooting the phosphor?) and heard some scary ticking glass sound similar to cracking ice if you've ever walked onto a frozen pond.