I replaced the two other grey high voltage caps in the frame and line stages. I then had a cramped picture at the bottom with a 3 inch band... I replaced the .015uf cap with a 0.1uf by mistake
. Once this was replaced with a 1kv 0.01 cap, order was restored on the screen and after more twiddling a nice even picture was produced. A display wobble slowly went away over the next couple of hours of use and the set 'wakes up' and moisture gets driven out of the set. The odd changes in brightness and contrast with changing scenes seem to get less and less noticeable with more use...or I'm getting used to it!
I found a quite acceptable picture can be obtained by backing off the brightness a little more than usual with reasonable contrast. The set has been on for about 4 hours and the LOPT does not feel warmer than a warm cup of coffee which bodes well. On screen text is now quite legible and even if the definition is not great, it is acceptable. The damp smell is taking longer to disperse but with the back on again the insides are getting warmer than with the chassis hanging out in the service position as before. Now to tart up the cabinet a bit, mend some scratches and find some nice little feet to stand the cabinet on and to ensure the ventilation slots in the plywood base are not blocked.
I guess that there is some sort of limit on video bandwith compromising the picture quality? Lack of black level clamping on a set of this size is also a limiting factor. Was this a cheap and cheerful set in its day? I estimate this set dates from 1972-73 from the date stamps on the original electrolytics so this example is fairly early production?