Hi Deejay,
Thanks for the information.
The mower has only had two owners, prior to me.
The original owner,a neighbour of my Father-In-Law, was using it in 1958 to mow his croquet lawn.
He became ill and my Father-In-Law did the mowing for him. When he passed away in about 1967, his family gave it to my Father-In-Law. I know that the BSA motor was on it when Father-In-Law got it.
As I said earlier, the guy who serviced it in 2012 said that he had only seen one other with the BSA motor, and from the sound of him on the phone, he has been around for quite a while.

However, it's now causing me a bit of a problem, as we are in the process of getting the Father-In-Law's place ready to sell, and we are also downsizing, so I really would like to see it go, preferably to a good home.

I'm loath to just put it on gumtree, I'd much rather it went to someone who appreciates the engineering in this unit.
Any suggestions on solving this problem would be appreciated.
Regards
MSR