W124 bosch fuel pumps

[Klasse]

The fuel pumps (twin pump setup) on my 1990 260E appear to have had it. They are noisy and delivering half the fuel the should.
New bosch/mercedes replacements are fearfully expensive so I'm looking at the options. Early 6cyl 124s had a single pump setup. Pattern pumps for those are cheap, but the later twin pumps are more difficult to find and expensive. Part number is bosch 0580254950 or mercedes a0020918801 replaced by a0030915301.
There are some pumps on eBay that claim to replace that part yet appear to be exactly the same as those on the single pump setup, which is a different part number, others say different. I'm confused. All these bosch pumps and their copies look the same.
Any ideas?

 

[carat 3.6]

There are differing part numbers for the same pump, depending on the fitting kit that comes with it. However an early car with cis injection has different pumps to a later car with efi.

As a rule, the earlier cis pumps are the better one's to have. I normally fit 2x bosch 0580254911 to a 6cyl car.

 

[kth286]

My late 1995 124 6cylinder has the later (different type) single pump.

Still going strong at 195,000 (ish) miles.