Hi Jamiep,
I have only just seen your post,I have spent 100's of hours driving JCB 3C, good machines for their day, the last of the 3C,s were much better with the "Powertrain" transmission. Prior to the Powertrains we only ran the ones with clutch and 10 speed gearbox, I remember arriving back in our yard in the evening and changing the clutch so it could be back out the next day. I remember we had a 1976 3C that was a particularly good machine the engine ran like a "sowing machine". I remember being stopped by the Police on my way back home from Ladle wrecking with the rockbreaker at a Sheffield steelworks around midnight, they thought it was unusual for a JCB to be on the roads at that time of night, they were wondering if it had been stolen, which was good of them.
Are you thinking of buying one to use or restore?
Ex tractor fan