Finish ID question

I just inherited a bed and the finish on it is gone in many places, but without wear marks. It's like it faded over time. The problem is I live in a very humid place, and moisture is causing the underlying stain to transfer. It's from 1957, has never been refinished, I think it's a maple veneer? I used some amish wood milk to get water rings off and it appears to be further taking the finish off, which I didn't know was possible. Any ideas as to what this finish could possibly be?