That "muffled chunk-chunk" description brings back childhood memories of a belt-driven refrigeration unit at a neighborhood mom & pop grocery store.
I'm no expert, but it could be that your fridge is operating as it should now, with slack allowed for some additional mechanical noise after having been in nearly continuous operation for over 80 years. No doubt the "use it or lose it" postulate has been a significant factor regarding your machine's longevity.
If you're like me, you probably won't be satisfied until you've exhausted all options to quiet it down further, and I would not be surprised to subsequently find out that you were successful.
Congratulations, and keep us posted!
I'm no expert, but it could be that your fridge is operating as it should now, with slack allowed for some additional mechanical noise after having been in nearly continuous operation for over 80 years. No doubt the "use it or lose it" postulate has been a significant factor regarding your machine's longevity.
If you're like me, you probably won't be satisfied until you've exhausted all options to quiet it down further, and I would not be surprised to subsequently find out that you were successful.
Congratulations, and keep us posted!