Thanks Jerrt Lee Marcel.
That's a really good advice. By head I guess you mean the pcb outs (signal and voltage polarity). Am I correct?
Is there shielded wire of such small gauge (or could I create one by "knitting" 2 wires)?
In my case what would you do to achieve my goal?
I mean it's highly improbable to find a donor body capable to host all 4 pcbs. Even 3 of them (and forget about fig. 8.