I'll throw in my 2 cents for what it's worth. I've owned my MB since 1997. Your '85 is 6 yrs. older than mine. You ask about 3 different types of pumps, but in today's world, I wonder if there are 3 types available? These days, you find yourself left with 3 options:

1. Dealer - outrageous prices

2. Uro - Chinese - near as I can tell, Febi/Meyle may be no better than URO.

3. Salvage yard - for me, ok for specialty metal(nuts/bolts/brackets)

My OEM fuel pump lasted 13 years. It was a single-pump Pierburg. Replaced it with same Pierburg part #. 13 years later pump #2 is dead. Pierburg no longer available.

My options were a new dealer pump or a Bosch pump. I opted for door #2.

Options are drying up.

__________________
Mike Murrell
1991 300-SEL - Model 126
M103 - SOHC
"Fräulein"