Quote from Mooh - "The first Fishman style soundhole pickup I saw was actually the precursor made by someone else who supposed sold or licensed or whatever the idea to Fishman. If I'm not mistaken it was English in origin."

That would be Mike Vanden (originally from Stockport but now living in Strontian) he now produces an improved version - the "Mimesis".

[I do wish people would stop calling u/s piezo pickups "transducers". A transducer is a device which converts one form of energy into another. All pickups are "transducers", a guitar itself is a "transducer", even a lightbulb is a "transducer"!]