[Hallicrafters] SX-28 and SX-73 variations

[bob at krassa.com]

I have an SX-28 in a cabinet on which the chrome strips have only two, 
instead of the usual three, parallel ridges.  Other than that the cabinet is 
standard SX-28.

I also have an SX-73 with a faceplate painted in hammertone gray, on which 
the white lettering is some sort of decal and not silk screening.

Does anyone know if either or both of these might be factory variations?  I 
thought for sure the hammertone on the SX-73 was done later until I was 
informed that other Hallicrafters radios in the 50s were occasionally 
painted hammertone by the factory, and it looks professionally done...

73 de Bob Krassa KC0TDS