A Yamaha 125 TZ FRP repro piece by Air-Tech was chosen. The sub-frame was built to fit this pan:

A Dremel cut-off tool was used to revise the shape, the paint is rattle-can flat-camo.
A billet 40-LED tail light intended for the chopper market was lathe modified to fit it's fabricated alloy bracket. This assembly bolts to the sub-frame allowing seat-pan removal without disconnecting any wires:

Tractor tail light was in a box of items purchased at a farm auction:

The tractor stop-lens is secured to the seat-pan with silicone:

Thick-n-thin stripes, number graffix, and neoprene pads.
The neoprene was bought in a sheet, cut, carved, and sanded to shape.
Two screws remove the seat-pan from the sub-frame:

From the top:
