The photo below is from a 1949 motorcycle parts catalogue,could this be the same seat fitted to WD bikes such as the Nortons below,also fitted to some BSA M20s & Matchless G3Ls,could "WILBY" be the model or maker?

Steve it looks like A E Wilby were the manufacturers of mainly bicycle saddles. But I'd be happy to find one of those 1949 "Loaf" bum pads.

https://www.google.co.uk/search?q=A+E+Wilby+&sxsrf=ALiCzsZ9YDYO3SVKsfMmv3ZAaLQ4FbncPw%3A1660335140478&ei=JLT2YqvrHJG78gKs-ImoDg&ved=0ahUKEwirjYayjsL5AhWRnVwKHSx8AuUQ4dUDCA4&oq=A+E+Wilby+&gs_lcp=Cgdnd3Mtd2l6EAwyBQghEKABMgUIIRCgAToHCCMQsAIQJzoECCEQFToHCCEQoAEQCkoECEEYAUoECEYYAFDwE1jHWGCGcWgBcAB4AIABe4gB7g-SAQQyMS4ymAEAoAEBwAEB&sclient=gws-wiz

Cheers Ron

email (option): ronpier@talk21.com

These were most certainly the original WD motorcycle pillion saddles, but 'Dunlopillo' was almost pure latex and once the Nips had taken Malaya, it was unobtainable..Hence the move to the complex steel-framed constructions.

These early 1941 bikes are the earliest images that I have of machines with full pillion equipment.

These seats are seen on many BSA riders instruction books too
I managed to find 2 of them over the years
Br
Jo’b

email (option): jonnyob1@googlemail.com