I'm trying to open an OSS manually... as far as I can establish, there should be somewhere to pop an Allen key in and wind it, but not immediately obvious to me where!!
Seemingly (having had a quick search with Opensky and Manual as search terms) you remove the cover for the light and the emergency manual OSS allen key socket should be there. I think the allen key is also stored in there as well?
However I've not done this myself so cannot comment from experience.
Only a few more bits to salvage, then off to the ally smelter in the sky . A once beautiful and highly specified 1.4 petrol, destroyed and written off by catalytic converter theft