TA8427K is your Vertical Processor/Deflector and is a available at MCM Electronics for 1.17 each
TA8403K is your Vertical Amplifier which is not available from Toshiba, but a suitable sub will be NTE7158
You are correct the PDF that I referenced was just a drawing for you to look at. All the vertical circuits are very similar. I have worked on 1000’s of CRT units, out of them all 90% were capacitor failure, sometimes the IC, and 1 time the yoke. To correctly troubleshoot this unit you need to look at the vertical frequency. I didn’t mention this because I don’t think you have a scope to look at signal, and your knowledge of electronics is limited.
What are the reference numbers in the circuit you are working on? Look for electrolytic caps in that section. From your pictures I would guess the second heat sink behind the one you reference is where you might want to look, but also realize that all the components don’t have to be right there, they could be in another part of the board. Kind of the reason we like to look at the schematic, it helps us find the faulty parts, but not all the time are they available now, and now you have to use your experience.
Since you have referenced no model number for your TV, I can only give you knowledge of the circuit and my experience troubleshooting CRT units.