I found a link to one like yours in good shape.
IMO, the only reason to keep/use it is nostalgia, a family heirloom, remember grandpa.
I would not spend a lot of money on it. IF you want to keep it and get it to sound better, you might try a full set of new tubes, AND the controls could use cleaning with DEOXIT; both of which you can do yourself. They had good components, it is likely that will be all it needs to sound good again.
Clean the controls then put the new tubes in right away. Oh happy day, or; if it doesn’t sound good, return the tubes, try to sell it on eBay ’as is’.
Next, IF the tubes/cleaning worked: what cartridge/needle (needles are called stylus) is on the Garrard Changer? It’s stylus is probably worn a lot. Again, for nostalgia, look for a replacement needle (stylus). That will definitely perk up the sound of your LP’s
Probably find a new stylus here
Record Changers are not good for your LP’s, they scuff when dropped on one below, so only stack one to play.
Among Fisher Consoles, it is not the most special. It has cone speakers (their better consoles used horns and bigger woofers).
i.e. I inherited a Fisher President II Console, my uncles.
I moved the speaker parts (horn tweeter, horn midrange, 15" woofer) to a new rosewood enclosure, they still sound wonderful, I remember my uncle every time I play them.
Got rid of the Garrard Changer, Viking Tape Deck, Fisher AM and FM radios, Preamp and the large Cabinet. I used it’s separate pair of amplifiers for years, they were special, I sold those amps for a good amount of money.
Best of luck with your project.