I must say the service manual is amongst the best described I have seen.
The scope is a mixture of semiconductor device and valves technology. Opps! Sorry, I have got to raise my hands up in surrender.
Can I say is a paid headache, buy someone else trouble so to speak.
I mean there are a lot of cheap better scopes around and I don't think you can go anywhere with this one.
Let it go, man, lost a few dollars but don't lose your time on it, we call it cut loses.
No offense, just my opinion when I see my grandfather technology in pain.
BTW, put the country of yours up and I am sure your country men will be eager to help out.