Driving over the past week I have noticed the speedo needle dropping to zero then bouncing back up. The mileometer seems to be doing it's job so wondering can this be fixed. If i am out in the Scooby I do have my road angel on and use that for the speed.

 

Could be a bad connection between speed sensor and back of clocks rather that faulty speedo, I would check all connections, clean then up and add a little contact spray then see if it helps, if it doesn't then you can investigate further

 

If this is post 97, ie: white clocks, then the above advice is good.

If it's pre 97, it'll have a mechnical drive. That may also be suspect.

 

Did not make clear it's a bugeye.

 

Then first instructions are correct:

Could be the gearbox sender, the connections to it, (likely), the wiring in between, (also likely), and the speedo itself.