[TowerTalk] Gold flashed relay contacts useful for antenna relays?

[Richard (Rick) Karlquist]

Can anyone tell me if gold flashed relay contacts
solve the problem of using the same relay for both
transmit and receive?  In theory there should be no
minimum current needed, but you wonder if putting
5+ amps through the contacts will wear away the
gold flash.  There are also issues of mechanical
wear, and contamination accumulating on the surface
of the gold.  I am looking at some 30A heavy duty
relays by Line Electric (series "STM").  Since these
are designed for hot switching, and I am only doing cold switching,
I am hoping that the gold flash will hold up.
I wonder how long it would hold up with hot switching.
Is gold flash isn't good enough, what about gold
plating?

I have a NOS Line Electric STA-2D that may be decades
old.  The gold contacts have the appearance of
a coating of grunge.  If I rub my finger across the contact, it 
immediately gets polished to jewelry store standards.
Is this grunge merely a cosmetic problem or something
I need to worry about?

Rick N6RK