'81 380 odometer hookup question

[RickM]

Passing this on from the Yahoo 107 group....

"I have an '81 380SL, the odometer has not worked since I got it. The
speedometer has always worked properly. I just pulled the guages and
everything seems to be hooked up. Both the speedo and odometer are
electric.

I know that the transmission has been rebuilt (before I bought it).
Can anyone tell me how to trace the problem of the odometer? Where
does it hook to the transmission? How can I pinpoint if it is the
piece that hooks to the transmission vs. the odometer itself.

ALSO:
If ANYONE has a drivers side seatbelt receiver (the part that hooks on
the side of the drivers seat that accepts the seatbelt and locks). I
need one.

Thanks
EEE"