Have available an original Aiir Compressor / Pump Assembly for a Series W109 300SEL 6.3 with air suspension.
Was sold to me as a rebuilt unit, which is consistent with appearance.
Looks straight and clean, shaft turns easily, and pumps air so I have no reason to doubt the condition.
However, I have not installed or tested so being sold as good used unit.

Priced at $350, including shipping within the USA (slightly more to Canada).

New pumps are NLA (No Longer Available) from any source, so buy this one as a spare if you don't need it right away.
My 6.3 is long gone, so clearing out the last of the M100 parts shelf.
See my other FS ad for suspension buffers and wheel chocks for the same vehicle.

Cheers,
Peconga in Boise, Idaho