Thanks for both suggestions!
I'm not sure I understand though.
David Hess: I looked up collett sockets and came across these -is that what you're referring to?
So a resistor for example can have its leads/wire pins pushed into those pins and stay there? But I imagine it would be easy to bend/break the resistor leads as well.
On second thought: can pin headers be pushed firmly into those? In that case I could solder the resistor across the appropriate pin spacing and simply plug it in when needed.
Nusa: I'm not sure if I've understood you correctly, but perhaps (after soldering the pin header rows in place provided the spacing allows for that) I could use Dupont connector for both the components (soldered at the appropriate distance, using a suitable number of pins for that spacing) and the "skip some pins" jumpers. And that way I could build up a complete "configuration sets" for a particular voice card setup, marking each connector with where they are to be used (i.e. "J7" or "R15" etc.) of course with a small dot of paint on the first pin on the PCB jumper and the connector to get the key pin right.
Or for the "flexible jumper" (i.e. skipping a pin in some configurations) I could use two 1-pin Dupont connectors with a short wire soldered between the two. But I'm leaning towards bulding dedicated "configuration sets" with connectors that just plug into wherever they're needed, each set neatly organized in their own resealable plastic bag.
The external PCB with the components and switches needed sounds elegant, but I'd have to find a place to mount it (so it won't just hang loosely around) and perhaps the long wires would cause noise problems etc.
It's funny how the creative juices appear when you start discussing things