I hope this helps, Ghost. I didn't want to remove the seat if it wasn't necessary as I don't like the risk of damaging paint or fasteners. As I'm sure you know, it's impossible to remove and reinstall the side cover and "leave no trace". What I can see up under the seat is a multi-pin plug, presumably feeding the rear lights. I tried to take a picture up in there but it's so fuzzy as to be useless.
Yes Che, it's a Barkas B1000 from 1987.