Addendum.
I took with me a very old B 17 saddle with me to see if the leather could be replaced. I sorted this out with Steven Green uk service manager
It had an oval embossed side badge which was well worn and the leather was badly cracked. Early 1950's I think?
What I wanted to preserve was the chassis which is a lot more substantial than any of the modern ones and it has bag loops .
Email received Monday evening to say refurbishment completed. Saddle delivered today ,well chuffed with the quality of the workmanship.