[Username1]

In the attachment you can see the top scope image - drawing the transition
point is where the scan line comes close to the center of the tv screen....

This puts the problem in the damper circuit.... Possibly this is a problem
with a capacitor effecting the shape of the wave as it's close to it's discharge
point, - before the next on time for the horiz output tube....

I'm going to say it's a capacitor issue, not a tube issue.....

(your pictures)
In that first picture on the right side of the screen, it sure looks like the end of the
box is no where near box shaped.... quite a pronounced bow in it. And in each
of the pictures you posted it looks like the lower right and left sides of the picture
are very out of focus..... and the line defining the box in the top picture sure
looks to be pretty wavy.... Are there other issues with this set...? Is the B+
where it should be....? is it as clean as it should be...?

.