3 quarts of ATF is less than half of what should be in there. Sounds like they changed what was in the pan but didn't drain the torque converter. Makes me wonder if this shop works on many MBs.
Antifreeze seems cheap at $7 compared to everything else so my guess is that it's Prestone and not MB or G-05 as is more frequently recommended for these cars.
At 30K miles I'd expect to have the brake fluid replaced with a fluid cost of more than $2.25.
I'd also expect a power steering system flush and fill and a new power steering pump filter.
83 300SD ... $950, see cars forum