IME you'll not be able to remove the rust without removing the gold wash. No way, no how. I have a Torrey, and a couple of Dovo (Fritz Bracht) with rust under gold wash like that and I just leave it be. That razor is worth whatever for the scales more than the fancy blade.

Decorated celluloid scale collectors pretty much don't care about the blade. It would probably hone up to be a good shaver.