Gearvendors overdrive for 904

I have an undriven gearvendors overdrive unit to fit the output of a 904. It came installed on a trans that was never driven, but installed on the POs car. I was going to install it on my early 904, but it wont work.

it includes the speedo gear thing, supplied wires, and control box 1E171109.

asking $1500usd OBO, located in calgary, alberta, canada