After lots of late nights reading on Facebook in several SW groups and offcourse on the SilverWing 600 forum and checking out the World Wilde interWeb. I made my one of kind backrest 2day. Took it for a short ride and I'm happy sofar.
It needs thicker iron support, next week I'll check some shops in my town.
For now it's a great improvement for riding in comfort.
Hopefully I can finish it next week completly.
Have a great day en Stay Safe
Greetings from The Netherlands