[Flash75]

Do you mean the rotor and the points cam are spinning or is it just the rotor spinning. If only the rotor you can replace it. There a tab inside the rotor that should engage a slot in the top of the distributor cam. If the cam is spinning you will need to buy a distributor unless you know how to disassemble, inspect and repair a distributor. If you need parts other than points, rotor and cap you may not be able to find what you need. I assume you have a Haynes MGB manual or some other repair manual if you need to disassemble the distributor. Let us know exactly what is spinning and perhaps we can help you.

Clifton