The MT75 pedal box is 36mm narrower than the standard one, making it 214mm from side to side across the base (the 250mm dimension at the bottom of Fig 4.37 in my copy of the book).
The MT75 dimensions aren't symmetrical so you may have to adjust U7 and U8 to make this work left hand drive.
If you want more detail I've a printed out copy of the modifications that were posted before and could scan it in. You'll just have to excuse the oil stains
Matt