OK the conv is off in the center & you wont get the sides
right without the center. CRT looks strong, grey scale off a little
try a little green.
So why is it off ? May have always been like that ? Another
theory is the neck magnet has changed by sitting in the same
place for 30yrs by the earths field. If it were me I would
mark the magnet so you can put it back then cut the tie
and try adjusting it. Without a set of rings thats about all you can do.
73 Zeno