Here's some photos. I'm metric challenged, so these are inch approximations. Seat mount rail center to center is 16 inches. Seat bold holes are 11.25 CC and 10.25 CC.
Bottom of mount rail (where it bolts to the sides of the door sill and tunnel) to the top of the seat rail at the rear is adustable at 3.5, 4.0 and 4.5 inches. Front is fixed at 2.75 inches.
I can get the exact dimension you want if these don't do it.