Unfortunately I now find that the doors are not as easy to fit as I first thought. I took the measurements from the plans for the garage. What I did not know at the time was that the all thou the brickwork on the outside face of the garage raises straight from the ground inside it is different. The brickwork piers do not raise to full height only as far as the lintels over the doorways.
The brackets to hold the roller doors has to be fixed above the opening but in the same plain as the vertical tracks for the doors to run in.
Seems that I will have to extend the brickwork piers up and have the tracks for the doors mounted on the inside face of the brickwork.