Wow. Okay, lots of stuff to think about there.

Initially, though, I'm going for minimal modification -- just the DC blocking caps, and keeping the +12VDC PSU (since the PC has +12VDC readily available, no big deal there).

I fully expect the port isolation figures to be quite bad, especially compared to the 60dB+ that the mechanical Frankenswitches give. But it might be good enough for typical needs. We'll see.

But, alas, the one and only electronic component shop in town closes their doors at 5pm on Fridays, and doesn't reopen them until Monday mornings. So this project is (mostly) on hold for a few days now.

Cheers!