Finally after changing various parts the I-may-get-sick-but-never-die 528e sprung to life.
This is the longest (a week and a half) this car has not run since I bought it in 1995 with 167,000+ miles.
The following parts were changed within the last two weeks:
In-tank fuel pump $68 Friend-owned shop
Sending unit $79 Friend-owned shop
Fuel filter $15 Dealer
Fuses* (all) $5 Autozone
Fuel pump relay $21 Dealer
Main relay $10 Dealer
Spark plugs** $10 Autozone
Battery $25 (prorated) Autozone
After this experience and reading about how many parts can affect the car not starting, I would recommend that one begin changing the least expensive parts first and progress to the more expensive ones.
*I was surprised at the difference in the electrical system of the car
after changing all the fuses.
The radio no longer crackled, the interior lights seemed brighter and
the key-in-ignition signal was very audible, when even after changing
the battery, it could not be heard.
So for about $5 you can change all your fuses in the fuse box.
**In the past I have tried the four prong platinum plugs and the basic
platinum plug but my car did not burn them well after approximately
six months in use. Both times after removing them the electrode end
looked as if they had been scraped in the bottom of a dirty oil pan.
While I have used Bosch Super in the past, this time I was in a hurry
to get my car running, so my wife could her vehicle back (but more
importantly I could drive mine) I bought the Denso plugs from
Autozone. It was painful to put Japanese parts in a German car but I
went through with it and so far so good; besides up to this point only
three people knew.
I'm very grateful to all who responded to my novice questions about resolving the no-start problem. It's amazing to me how individuals who have never seen or even heard each other are drawn to the same place in the commonality of a particular automobile. Thanks for being out there and willing to share your expertise with others unknown. Please continue to do so.