Spot the difference??? 
I got the Motometer back from the firm that overhauled it for me - Speedy Cables
http://www.speedycables.com/repair.html
They have done an absolutely awesome job in my opinion - spot on Boys! Many thanks!
A few more pics of what the gauge was like when I got it and what it looks like after a proper overhaul by real professionals
The gauge has been thoroughly cleaned and repainted internally and externally. The face and needle have been beautifully restored even down to the luminescent marks (hopefully with non-radioactive paint 
). It's been repaired and fully tested for function and accuracy - Brilliant!
And of course the big question, does it work??
Of course it does....Like a charm! It took just a few minutes (with the usual contortions needed for any jeep gauge work) to get the repro Stewart Warner gauge out and the Motometer in. The cable fitted straight on without even the most minor resistance (Cable from Tony Sudds, TS Autos). Quick test drive (it was raining again!) and Bob is your Mother's brother! Perfectly restored original Jeep Speedometer.
I sit here with my pint of "Old Moggie" Bitter (my one holiday present from Devon), feeling exceedingly satisfied with my auction site purchase and its overhaul - job well done and jeep significantly improved. 
As a matter of interest here's comparison pics of the repro M38/CJ2 gauge compared to the original Motometer
Original gauges are quite rare so I'm very proud to have got this one and been able to put back in the jeep in such first class condition.
I wonder what the change of mileage implication is for my MOT certificate????
For All Your Jeep & Dodge Needs
http://www.dallasautoparts.com/