[Hallicrafters] Chassis coating

[Roger K8RI]

What is the yellow plating used on most of the Hallicrafters chassis I have? 
It appears to be a flash plating of some kind.  Flash, as in a chemical dip 
when a reaction takes place leaving a very think coating.

I've found for rigs that have a lotof dirt and have not been kept in a 
heated area this takes on a mottled apearance which is not a real problem. 
On the ohter hand, I have one SX101A where most of this is gone on the 
chassis for about a half inch behind the front panel which you can't see any 
way unless you take the front panel off.  These spots don't look the same as 
rust spots, but I'd guess they are related to the dirt and moisture.  I'd 
like to clean this up, but without any abrasive such as a Scotch Brite (TM) 
pad.   On most of the chassis I've been able to clean it nicely with just a 
damp cloth, or damp paper shop towel.

On one HT-32B the 10 meter coil cover looks new, but the coil cover next to 
in looks pretty bad.

Any thoughts, or socially acceptable suggestions?

73

Roger Halstead (K8RI and ARRL 40 year Life Member)
N833R - World's oldest Debonair CD-2
www.rogerhalstead.com