Without going into the set and taking readings, you wont get very far, ALL 3 , G2 ,G1 and focus are driven from the 540v boost (ref 4 SAMs) from the flyback, if that is wrong, it will mess the screen pretty much like you are seeing.
There is also a 47uf cap in the screen circuit that may be bad.
The entire boost path from the FBT to the CRT must be checked.
It was very easy to find a copy of the sams for the set.
1493-3-2.pdf
https://drive.google.com/file/d/1wV2...Fz1qtfez3/view