This post is really just to record info for thos who use the search facility.
The ABS Master Cylinder on my 1996 van failed. I believe it is the same part number for all pre 1997 transits with ABS.
The ATE part number on the side is 10.6123-0150.3 when searching for this no results can be found (i.e. not available anywhere). The ford FINIS no for it is 7143733. Ford no longer have a stock (no suprise there).
But the original ATE part no. Has been superceeded to 10.6123-0154.3 - which is readily available (but not cheap)