[Hallicrafters] SX-100 knobs

[Gerry Steffens]

It is a paint.  It chips off and it is only on those two small knobs.  All
others are normal silver.

There is currently an SX-100 on the bay (# 121521093822) with the gold knob
inserts.  From my experience, the gold inserts are only on the one version,
Mark IIa, or maybe mark IIb.  I ought to be whipped with a wet noodle as
back in the mid 1990s I once had another receiver with the gold knobs and I
sold it and forgot to swap the knobs.