Bit of an update. Right after I got towed home a few days ago I started my 2 year service and drained the oil and the car sat for a few days with no oil, so I couldn't start it up. Today I finished up with the oil change and started the car up. It started nicely and all the gears clicked into place, although I never took the car out of the garage yet. That will likely be my next step.
But I checked a few things. The lights on the shift lever did not light up and I thought "Aha, I have found the problem" as suggested above. Then I thought that maybe those selector lights do not light up in the daytime. So I turned my headlights on and the lights on the gear selector all worked like they should. I did not even realize that those lights don't light up unless the headlights are on. On my other cars those lights light up with the headlights on or not.
Checked the tension on the belt and it is nice and tight.
Coolant level was okay.
So my next steps will be a drive around the block to see if anything has changed Then if that works out okay, I'll make a run to one of the McParts Auto stores to get the codes read. BTW the check engine light is still on. Depending on what the codes tell me, I may have to buy my own unit specifically designed to read the Mercedes codes.

__________________
Len
'59 220S Cabriolet-SOLD and living happily in Malta
'83 240D 351,500 miles original owner-SOLD
'88 560SL 41,000 miles - totaled and parted out
https://sites.google.com/site/mercedesstuff/home
'99 E300 turbo 227,500 miles
'03 SLK320 40,000 miles - gave to my daughter
'14 Smart electric coupe 28,500 miles
'14 Smart electric cabriolet 28,500 miles
'15 Smart electric coupe 28,000 miles