w108,107 Parts Hoarder
Date registered: Jun 2010
Vehicle: slc5.0cab 280sl5sp 280se4.5 500sl92 GONE:280sl79 4xW114/5 3x450sl72-3 280slc4sp81 280s69 73,81SLCs
Location: Philadelphia Area
Mentioned: 27 Post(s)
Quoted: 1574 Post(s)
If you are talking about the turn signal lens on a North American 72-73 model, then these are still available from MB. The housing is supposedly no longer available. There's a picture of the lens (from the other side) below.
Since you say "under the fog lamp", I believe you are asking for nothing since there should not be anything under your fog lamp.