Stop in for a cup of coffee

Seems I bought a speedo. Auto Meter 6602. It seems to need some sort of special input, like from a Vertex magneto but I figured, hey, I'm an electronics engineer, how hard could it be? $60 plus shipping is an ok price, I think.
I bought a cool MOON tach from the 60's (new in the Box) from a guy here. Guy always has tachs for sale... Same guy ??