I believe they are merely his seat mounts for the seat pan to hinge using the original hinges on the frame. With a set of neopren or rubber sheet beneath each contact point it is a unique and nice way to provide a solid seat pan that can hinge up to access anything below the seat pan. I like it, having not seen that before.
Gulf schemes are cool. You know you are needing a nice Duc 900SS to go with it...
I like what you have done with it.
Good job!
So, you're kinda right....
The hinges where pretty beat up at the beginning of my project, so i opted to trim them off and do something a little different.
The seat pan slides under the tank grommet on the front, sits on the rails in the middle, and bolts to the rear frame loop on the rear with to small bolts. the two bolts on the rear should, eventually, serve to hold on the rear fender and license plate bracket as well.