The 2 big caps will be the most expensive obviously, while you're in there - or your tech. if you find one - I'd say replace all the electrolytics, they won't cost a fortune.
You could do with checking all the diodes too.
No armchair diagnosis is going to be perfect, there's no substitute for a real life inspection/repair/test.
I'd have a word with PJB first though.
Cheerz, John