I have a vintage Brooks B130 black (well, very dark brown really) solo seat complete with frame and springs. Rather good condition considering it’s age.
I was going to fit it to my TT Rep, but decided to stick to the original Lycette seat, which I am currently refurbishing.
If anyone would like it, you can have it for what I paid (and I have seen them go for an awful lot more) ; that is £60 plus p/p.
Let me know if you want a photo.
Chris.