Mikael,
After writing the above I just thought of DeTomaso as the owner of Maserati. They used parts from each other in that periode.
I searched picures of Quatroporte III, and believe I found the exact part.
And here's something from ebay:
http://www.ebay.com/itm/82-MAS...AOSwo3pWeH-J&vxp=mtr
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