Sorry, I forgot some of the important info. The car starts easily right after it dies, and its always when coasting/braking. As for the parts already thrown at it, the crank position sensor, overload relay and fuel pump relay were replaced on the first visit. Then two fuel pumps were replaced along with two fuses. The third attempt was to put in a used EZL control unit. All new parts are said to be genuine M-B parts.
This is what I know, the "expert" has never driven the car to try and duplicate the concern even though she told him to keep it as long as needed to ensure its fixed. Also I've done a lot of internet searching and this sounds like a very common M-B issue, for all models, and for all of the posters who have had this type of coasting issue it was narrowed down to many of the items already replaced. Of the items that have cured others' cars the hall effect speed sensor seems like a logical next step.
Thanks for the replies, hope this you with what you all think I might test/check next. Andrew