I used vinegar in water and that really helped. Mine was a newer particle board cabinet. I did refinish it, but still needed to get the stink out.
It's now the cabinet my main machine sits on. BTW - the machine that came with the cabinet never got 100% smell free. It was fine until it got heated up in use, then I could just get a hint of smoke from it. Ended up giving it to someone that just needed a machine for odd patching jobs, so the smell wasn't a problem for them. It was a model just a bit later than the 500 is. One of the first open arm Singers.