This is something I've always wondered as well, how PRS shares out the fees that venues collect. PRS seems to suggest that it's done on self-reporting by venues or artists, including for cover bands, but this seems to be placing an awful lot on trust.
As I say, Bigsby, Fender, Les Paul, etc. were all contemporaries, hence the "cross-pollination" comment earlier. Fender may have nicked Bigsby's design but it's arguable what claim Bigsby had to it being their original idea in the first place.
But to be fair the Bigsby headstock design itself was inspired by headstocks used for much older stringed instruments. Alas my Google-fu has let me down and not taken me to an image I've found previously, but they're effectively a violin family instrument headstock viewed in profile.
They're selling in the neighbourhood of $1100 at Sweetwater in the US, so I'd expect them to be in the region of £900 if that translates from the current exchange rate, which is Fender Player series price territory
Do you have isolated power supplies for each pedal through a separate power supply unit, or are they daisy-chained and just plugged straight into the mains?