In July I posted a message about being able to select 1st and 2nd gear but to select the other gears I had to push the gear lever gently down then up. I had a number of helpful replies and I said I would post what the problem turned out to be should another member experience a similar issue on the old small block/big bore machines. It was the pawl (gear return) spring that had failed which resulted in the selector drum being unable to centre itself for the next gear selection unless I did it manually by gently pushing the gear lever down then up. The break in the spring was clean so no residue tiny bits of metal were floating around the gearbox. Another indicator of the pawl spring failing is the lack of tension in the gear lever as it flops up and down, The work was completed by a competent mechanic in southern Spain who charges 20e an hour which is the same rate car mechanics charge in the area. If you happen to find yourself replacing the pawl spring there is a useful clip on YouTube showing how to do it so the spring lies nice and flat on the plate when it is under tension.
Quite a common failure, that spring breaking.
Did mine at 48k as a precaution whilst I was in there.
Pedal is very sloppy due to all the slack everywhere, not least where the shift shaft exits the back of the gearbox.