Obliterated VoPo sunburst
 

Dear Experts:

I just bought a VoPo Luger (1912 DWM), whose VoPo armorer's sunburst proof beneath the holdopen lever was deliberately defaced, I assume by the importer in the 1980's, in an effort to hide the East German origin of the pistol. As hard as I try, I cannot decipher the number in the center of the sunburst. Does anyone know of a special, non-destructive technique that can help with this, such as some sort of special lighting?

Thanks,
Jeff