Hi Roger,
It looks like a washer is jammed into the rear of the mounting?
Have you tried to give it a whack and see if its movable?
John
John, just seen your post and you're spot on, see my email sent to Ben at Watsonian on 28 Aug.
When I cleaned up the inside of the hole I saw what I thought looked like a washer stuck to the back and tried to knock it off with a screwdriver but it didn't move.
On a more thorough clean up of the hole and looking through it I could see a join. It then dawned on me what it was and with a punch and a
out popped (jammed in the hole very tight) a heavy duty spring washer. At least it tells me that my A10 had a sidecar attached at one time.
Also photo below of the GP Manx I've bought from Watsonian. They're going to change the lights for it to be more in keeping with my bike (i.e. no indicators). Comes with a hood and tonneau cover. It'll be delivered in a couple of weeks time with the fittings for me to fit it myself.