Hello Norbert. Sorry for the slow reply. I have been busy.

I ran out of time to get the Simson working reliably so I ended up buying a Yamaha FS1E and completed the adventure on that.

The Yamaha was fun but I sold it after the ride and decided to just keep the Simson. Unfortunately, life got in the way and it just stayed in a barn that I rent. I have since moved city, changed job, bought a flat and got married. Now the owners of the barn have asked me to move it. So I saw my Simson again last week and now want to get it working again. Whilst I was there, I couldn't resist spraying a little bit of fuel in the carb and seeing what would happen... It fired up and ran as if I'd only parked it up yesterday!
Now I need to move my Simson to my new flat. Big question, could I do this in my car? Can a Simson be layed down on its side? Or would the gearbox oil cause problems? Alternatively, I may have to dismantle the bike first, including removing the engine.