[RallyJon]

Bobby, there seems to be something very wrong with your dimensions!

The 49.5cm width seems to assume that the adapters replace the removable outside stock early seat rail. If you do this, there are two big problems:

1) The centerline of the seat will move ~2 cm towards the outside. Since the centerline of the seat is already slightly outside the center of the steering wheel, this is bad.

2) The outside of the seat will also be lower in height than the inside by another cm, which is the thickness of the removable rail you're discarding.

If you're replacing the removable outside rail completely, shouldn't the outside adapter be both wider and thicker than the inside adapter to keep the seat centered and level?

The alternative would be to keep the stock outside rail and bolt the adapter to it. In that case, the adapters would each be about 2 cm narrower as the actual width of the early front seat is more like 45 cm between the mounting holes in the rails.