Anyway, after getting the C5 working on pedal power, I figured it would be a good idea to get it working for my Year 11 school prom entrance to be something different from the obligatory limousine entrance. To cut a long story short, after getting the C5 out of the workshop for testing a week or so before the prom, it seemed that however much I peddled the peddles, the wheels wouldn't turn. I traced this back to the splines engaging the drive from the axle to the wheel - these were made of a soft metal alloy (probably a zink alloy) and the splines on the axle are steel. Of course...the ones in the wheels had worn.
Without the facility to machine such fine splines in the axle easily, I went for the easy option - cleaning both sections thoroughly assembling together, then filling the space with JB Weld - a fantastic American product that seems to be an epoxy resin with steel powder in it. After this, a hole was drilled through the hub of the wheel and a roll pin driven in to ensure transmission of drive. In the end, although a bit of a bodge, it turned out very successfully.