Sorry, folks, but I forgot to update this until now.
It's all working now but as advised I did have to cut the lift arm to lower the glass and it is definitely not a one-person job to put everything back together!
The winding gear had stripped and I replaced the entire assembly. Having patience — and maybe an octopus to help — makes all the difference.
Thanks guys for the shop manual link and also the photos. It made a complicated procedure a lot easier.
Cheers,
John
