I have followed all the suggestions related to this problem as regards the speedo housing itself (taking apart housing, checking for corrosion, cleaning all the posts, etc.) and have come up dry. Last night I took apart the accuator that is housed in the rear end that sends a signal (I presume) to the digital connection at the speedo needle and moves the needle and odometer as the miles pass.
When I took the fitting out of the housing I looked inside and easily moved what looked like a slotted ring. From what I have read this connection between the actuator and the spinning drive shaft could restore the power to the electronics that move the needle.
Comments and suggestions please...