Good news,I've just been into the garage and tried it again and all gears now go into position very easily with the engine running.Ive only reversed it out of the garage and back in again so far but it was fine apart from some brake squeel,so looks like they will need a little freeing off as well.Be a good excuse for a blast into the Peak District over the weekend
I haven't done anything apart from leaving it 24 hours so I'm thinking Mark's suggestion in post #6 probably helped and just needed a little time to work.Thanks Mark
It's been a bit of a harsh lesson but I will make sure in future that it is not only started regularly but also moved when on Sorn.Thanks to those who offered advice,much appreciated.