It measures 50 inch from back plate flange on tube, to back plate flange.(std english axle is 48 at this point).
And 54 inch from drum outer face (where the wheel fits)to drum outer face.
I will rescue it from under the pile of stuff at the weekend and check the ratio and any part numbers if it has a tag still attached.
I can do a mondeo rear vented disc and caliper conversion on it when we know if it suits your needs and budget.