Ha ha, if I told you that i'd have to kill you!!
Seriously, its simply an off cut of 18 mm marine ply I had laying around, then there was the Bosch jigsaw, pencil, cardboard & scissors!!
Oh yeah, sandpaper, drills, files & 2 days.
I think i'll mask it off & spray the top-ring silver just to set it off a bit.
Don't tell me its unsuitable, I KNOW its a stupid choice, but then, what yo-yo decided to make the seat base from it ? Its cosmetic only.
You wont believe how the rear 'bumper' will be made, OR what from.