Additional history on the Colt Z-40/CZ 40 B can be found in the "CZ40B Club", a part of this forum.
I recently picked up a CZ 40B on an auction for a rediculously low price, and have yet to find the time to take this jewel to the range to exercise it.
I don't know how many were made befor Colt backed out of the deal, but it can't have been too great a number. The number you quote, 800 sounds about right, but who really knows, especially between the two 'models'?