lilac,
This isn't always the case but "generally" a good oiling will quiet a machine down.
Here is an example. I just serviced a Singer 328K. It's a mid 60s ZZ machine that uses cams. According to members of QB that know more than I do the mechanical design is poorly executed so the machine is noisier than it should be.
At any rate once cleaned and oiled the machine went from noisy like a thrashing machine to a bit noisier than a normal machine. A complete 180º turn around.
I'd give it a chance if you want it and it would add to your collection in some way.
Joe