Need preamp switch

I am posting under "amps preamps" thinking I will get help sooner... and no unkind words about my pre amp please.

I have a Ming Da modified tube pre amp that I really like.

However the input selector gets noisy with static every now and then, but will clear up with a few turns through the input selections. Pacific Valve will repair but I have to pay shipping which will be about $65 round trip plus the hassel of shipping.. Where can I buy a replacement switch? I can it installed locally.... Thanks