I have a habit of collecting wood cabinets that look that bad, and dragging them home to give them a coating of "Old English Dark" furniture oil. You would be amazed what it could do for that cabinet. I do not know if it would bother the decal because I have never run into that problem. For really dry wood I have been known to coat the whole piece of wood to seal out moisture.
I was given a rocking chair that a puppy had cut teeth on, that had all of the stain and finish, and some of the wood missing. I brought it home. Used a little sanding to make it smoother, not perfect, and then used the "OED oil" on it and until I point it out, no one sees it. I do put a couple layers of oil on the really dry or scratched areas. Best part is the color of the oil hides a multitude of boo boos. I also use it on my dining table to protect the finish from wet glasses, and hide the rings it got before I started oiling it.

i have the same cabinet and machine, also with a rotted out base, though my cabinet does not need refinishing. i like the idea of replacing base with a piece of oak plywood. I'm assuming that could then be stained to match the cabinet's colors?

I tried alcohol and it didn't seem to do anything but make it sticky for a couple of minutes then go back to normal. I tried some formbys and that worked on most of the finish but there's still a lot of what feels like rubber cement. My rags is stick to it like it was Scotch tape. Is that some kind of wax? Polyurethane?
And did they rub some kind of black stuff into the grain in those days? I'd like to get that out, but it's not as important as getting the crust off.

No it is shellac that gets sticky. You need to keep going with the alcohol or the formsby until all the sticky is gone. It is not a quick process. Just keep scrubbing until all finish is gone. You will know when it is clean when the wood looks dry with no shinny areas and no sticky anywhere. Don't use oil to feed the wood. Wood is dead so no feeding is needed. It is the finish(shellac in this case) that gives wood the glow you want. Of course the stain gives the color such as light or dark oak then the finish brings out the color and makes the cabinet pretty. The cabinet could have been waxed by a previous owner at some time. Take your time and it will come clean.

It is indeed a slow process. The doors are done and look better, if not great. When I'm done I'll send a picture.
Thanks for your patience and help

You never have to apologize for showing us a pretty little vintage machine. :)

The painter's tape Glenn mentioned will work. That's how they masked off the original jack instructions on my 66 Mustang when they repainted it. It worked great and didn't harm the old paper.