[nocusr]

Thanks for your replies.  Tried cleaning, started with plain water and went only as far as Windex.  Cleaned up somewhat, but it's not just dirt, but approaching rust.  Looks like my two options are either a 0-100 logging scale, not 100% sure the size, mounting centers are the same, or the white dial from Radio Daze.  It's a paid restoration, so I'll have to check with the owner.  Thanks again everyone.