Peter, if I recall correctly, your Mazda gearbox problem is the only one mentioned on Talk Morgan, did you ever establish the cause of the problem?
To quote Vitesse:
"The issue was that the shift rods became out of sync, possibly due to gasket/ seal wear but we cannot find any other issue. We have replaced all gaskets and seals as required, including the rear oil seal which was heavily worn."
It sounds to me as though there was not really any satisfactory explanation. Hopefully it will never happen again!!!!!!