Hi!
I need to replicate the fixings of the seat (the removable part) of the F1 and I would need a clear image of those pieces.
I would appreciate your help
Regards

The special screw shown is used in 3 places circled in red

not those parts, those that go in the part 25

Pretty sure the base is just an 'L' shaped piece of plastic or thick cardboard about 6mm thick and is 19mm or so smaller than the edges of the seat cowling edges. Probably not too difficult to replicate as it isn't curved/arced underneath because the seat cowling is flat in the seting area. The hard parts would be the special bolts and spring clips that hold it in. I'd use Velcro.

Same did not explain me well , I would like to know how are the metal parts that go in the saddle that is extracted and that fit in the part number 20.

As I recall the seat base has a metal spring clip with parallel wires approx. 6mm apart that spread over and clip around the "special" bolts on the cowling. I think the clip is just pop riveted onto the seat base. They are attached over holes drilled in the seat base. So the wires spread over the conical part of the bolt and clip into the reduced diameter at the base of it. Pretty clever actually.

is what I want to see,

I haven't got the wire clips, but this is the pin