IIIa black , conversion or real ?

[photovdz]

yes... i love reconstruction of history... I dream of finding Capa's or HCB's leica (or contax)...

 

[Dralowid]

Yes, the inside of the baseplate is showing chrome under the paint.

 

[L David Tomei]

That seems like it's the important clue. I would think that the chrome had been stripped, removing some but not all the residual Wismut metal from the engraving. The numbers were probably cleaned by re-engraving since it is a bit more wide but clearly done by a skilled person. Never did this so I don't know how the repaint was done to preserve the Leica logo so well. David