southtexas
·I try to give my interpretation of the problem.
I had a similar issue in another sm300 bezel:
Basically the black paint which is below the acrylic disc for some reason (probably moisture?) tends to leak from the bezel. When I tried to wipe it from outside the result was more leakages, leading to partial discoloration of the disk itself.
Very interesting! I have a bezel that has several spots where the black paint has completely “vanished”, turning portions of the insert translucent and allowing the metal of the bezel to be seen through the insert itself. I wonder if it had a similar issue to what you describe sometime in its life.
Edit to add: if indeed your description is the problem here, I wonder if the black gunk/paint around the edges can be cleanly removed, and then replaced (resealed) with a clear resin. OP might send these photos to a bezel restorer to see what can be done to rectify/remediate.
Edited: