Well . . . the verdict appears to be in . . . I think. There is a 2 wired clip that plugs into the driver's side of the tranny. One of the wires had been cut and (poorly) spliced by someone before I got the car. Anyway, I reconnected the wire and the speedo works fine. I looked for a cable, but didn't see one. But, I didn't look that carefully.
I think the clip is for the spped sensor for the cruise control. Thus, I am led to believe that the speedo is electric. Until I get under it again, that is. :so