Check the questions on this sale then google wassell. 
Yeah some people need to engage their brain (or google) before they open their mouths. I recall when I was a young-un there was another young bloke in Wodonga that had one of these bikes (not sure which model or any other details except it was a Wassell). None of us had never seen one at the time and he was promptly slugged with the nickname "Wassell" ... in fact I can't remember his real name now
Not that it's relevant here but I do remember he had a part time job at Whitehouse Motorcycles in High St at one stage.
On the Sachs engine and gearbox issue, I also had a mate at the same time with a DKW and it was the most unreliable bike I had ever known .. probably still is. It had a leading link front end too I believe. He is a qualified motorcycle mechanic and used to work at the old Bob Crosby Motorcycles in Wodonga and had raced motorcycles for years so he knew his stuff. When the thing actually ran (which was rare) I recall it had a 12 speed gearbox .. 6 gears and 6 neutrals. The sound of that thing revving itself stupid when the neutrals "appeared" .... the incredible ringing resonance between the cylinder fins, will remain with me until I'm gone
