Rowe AMI Disco 200 R-83 Sound and play issues

Greetings,

A caveat before I begin: This is the first project like this I have ever undertaken and I am not by any stretch of the imagination a "handy man"...

I inherited a Rowe AMI R-83 jukebox a few weeks ago. It has been sitting in a barn for 20ish years and to my mild surprise it powered up, selected records and played fairly well. It played the records pretty slowly but after cleaning and lubricating the table, post and pivot points that seems to be fixed.

I have three problems that are vexing me:

First, when I initially powered it up and played a record it would on occasion get much louder and very "tinny" (lots of treble) there was no rhyme or reason for this that I could tell. After giving the box a good cleaning (unplugging all the fittings, cleaning the connections and reseating them) the volume fluctuation is gone but now it is pretty quiet and the volume doesn't change much when I turn the knob.

Second, the sound is very fuzzy. I have purchased several new 45s to play and even the brand new ones sound fuzzy.

Third, the juke will play most 45s just fine but on occasion, it will kick one out it has been playing fine in the past. The machine makes clicking noises, almost like there is too much input and then the record gets rejected.

I have done the following:

Replaced the cartridge and the stylus
Unplugged, cleaned and reseated all connectors
Cleaned all terminals where wires are connected.
Checked the speakers in the main cabinet for damaged cones etc.
(if someone could tell me how to get into the lower cabinet where the bass speakers are, I would really appreciate it).

The tone switches on the amp don't seem to do anything at all. If I switch it to additional bass or treble nothing seems to happen. The switches are also pretty stiff and hard to move.

I would GREATLY appreciate any help that is offered. I would love to get this thing singing sweetly in the basement.