I rebuilt many many many jukebox amps over the years. Mostly Seeburg tube amp and Rockola solid state. But Rowe or AMI or whatever, we did it all. I don't recall ever seeing cap kits. I don't doubt they exist, but I just maintained a stock of parts and had no need. I did a ton of CRT monitor repairs for the arcade trade, and they did offer cap kits for those.
That said, I am not aware of any cap kits for amplifiers, and especially for a relatively unusual one like that. But such parts are easily available.