Whilst perusing this Website reference is made to the advantages to be had by
Silver-Plating of circuitry which operates at VHF/UHF frequencies.
VK6WG explains :-

CONCLUSION from above:-
YES Silver Plating does improve RF conductivity,
but probably only if you DIY!
Might be hard to find some Potassium Cyanide these days!

It is with great regret that I announce the passing of Wally Green on 7 March 2012
Even after his 100th birthday celebrations in August 2011,
Wally continued his activities on 144 MHz and above, continuing a long tradition of providing signals from Albany across the Bight and towards Perth.
His pioneering work with the late Reg Galle VK5QR in the late 1970s on propagation across the Great Australian Bight,
with world record distances on 1296, 2304 and 3456 MHz using home constructed equipment,
set the scene for others to challenge the then accepted theories of propagation at these frequencies.
A self-taught man he used his mechanical skills to fabricate parabolic dishes,
parts of the "plumbing" required for the waveguide needed for those frequencies, and showed extreme patience in locating the rare components needed and then successfully constructing the transmitters and receivers without elaborate test equipment.
More than all of that, Wally has to be praised for his willingness to share his knowledge and experiences with others and "to be there" when conditions were both promising and not so promising for long distance propagation!
He will be sorely missed!
Vale Wally Green VK6WG
From: Wally Howse VK6KZ