The new SpeedHut GPS speedometer came in.
Wiring is simple, follow the instructions. I used the yellow/black instrument lighting wires of the old speedometer. Yellow is +, black is the 'Ground'.
I reused the instrument housing, the instrument seating rubber ring, the rubber/ metal bolts from the old instrument.
I bought construction metal band, 4mm nuts (for the rubber/ metal bolts0, 7mm nut fixing the metal band over the GPS antenna connection and 16mm nut for the gear box. All real simple and along the lines of some of the V11lemans forum proposed installation options.
I plugged the 16mm cable connection at the gear box and removed the speedometer cable and drive.
I only used one rubber steel bolt fixing the bezel behind the speedometer, since the Tach has 2 bolts. In all, three bolts hold the old instrument housing from the back, instead of the original 4 bolts. The old rubber seating ring was cut into smaller rings, to allow for the old flush seating of the instrument housing to the gauge and the gauge to the dash plate. Without the seals, the gauge or the bezel won't seat flush. Reason, the 3 3/8" Speedhut gauge diameter is too tight for reuse of the old seating seal. As an alternative you can buy 80mm diameter O-Rings, as one member suggested. The sections of the cut up seal ring go between gauge and dash plate, and between bezel and gauge (on the backside). If you are confused look at the tachometer....and it becomes clear.
I left the big cut out on the backside (where the original speedo cable entered the bezel, and one bolt hole open, since they are behind the fairing and out of sight). I mounted the remote button gauge control into one of the dash holding bolt holes (drilling it out to 6 or 7mm diameter).
I added the original mileage to the odometer, works like a charm. You can do this with the GPS odometer.
Here are a few pics: