Thanks for your advise John and Brian, I have freed it. It is a bit awkward to try it on the road where i am. I lined one of the raised parts on the pressure plate in the slotted hole for the timing marks on the flywheel and ground the end of an old power hacksaw blade to a razor edge. I got a friend to press the clutch pedal in and i managed to push the blade through between plate and flywheel. I was quite surprised how it worked so well. Thanks again Stuart....
Thank you very much for that tip.
4688R had a stuck clutch plate. I adjusted the cable very tight, jammed the pedal down with a broom handle to the drivers seat, and used a kitchen table knife to slide between the plate and the flywheel. It took 2 goes, presumably 180' apart, but after a lot of cranking in 1st gear, the engine started and the clutch plate freed itself.
Luckily I did not have to take to the main public road. Best done on a private road or a dry field. My sloping lawn was damp, so I had to use my sit on John Deere lawn mower to tow the Europa to a place on the field where it could get traction. With 185 front tyres, the lock is appalling, but I managed to get the car back on to my gravel driveway in front of my garage.
When cranking the car out of the garage in reverse, it did stick in reverse, but another couple of cranks in gear, and it freed itself. They don't like being cranked in gear much.