So, a good story on this one.
I was riding today and a bloke waved me over. The 961 is a pretty rare sight here so I'm used to people wanting a chat.
After we got talking - he was the original owner of my bike. Knew it was it as soon as he heard it. Gave me a bunch of details about it's history - and was only to happy to go and search his garage for the seat.
Rang me this arvo and I now have it.
The moral to this story is, short loud pipes help