1913 LWC

The spots are raised off the surface, it looks like some sort of sticky gunk under the microscope. The flow lines, (luster) is still present under magnification, so it could have been dipped in something but it has not been polished or wiped clean. I detect no hair lines as if it were harshly cleaned.

I am glad you answered. I was wondering if your polarity ladder of solvents would work on those spots without removing the tone.

Here is the reverse