You probably noticed, BUT THEY'RE ALL THE SAME.
The only version not used was A 000 140 5860 (the most likely version, as that is how Mercedes spaces the numbers.
First three numbers are 'Group' second three is subgroup and last four the actual part.....)
Being a A 000 means generally this part was used on several models different bodies, like 116 123 107 etc, and in this case I would venture to guess ANY 2.8 liter motor .
I was at a yard yesterday and probably saw a couple of them.
How about a photo of the part and the engine compartment.
Then I can find it more easily and help you out.
What does your smog check values say ?
High NOx or CO or HCs ??
HC's were close, but passed at low RPM. (MAX: 191 / Measured: 191)
NO's passed at low RPM, (MAX: 1277, Measured: 1244) but failed at high RPM, (MAX: 1137, Measured: 1382)
I've attached an image of the one I found on eBay. This is exactly like mine.
In addition I took two pics of the EGR on my engine.