Seems like this would be a perfect niche market item, that a 3D printer could handle using ABS filaments. While it would not be pot metal, that could be done also. Print out the emblem in a starch material. Mold it, and then make you one off in a metal of your choice. Pop the mold clean it up, and paint it, or gold plate the sucker. Depending on the metal choice Powdercoating might not work.
You could mold it in lab metal, and powder coat that, if you wanted to spend some time molding the darn thing.
Or keep it a 1.7L badge and well just shock the out of them when you pull away.
Some people have taken multiples and cut and built a single. So in your case a 2.0 badge and a 911 #.0 3.2 etc.... and cut and make it, solder it back together or epoxy, and finish with paint or plating. If your going to plate talk to them, and make sure your process is compatible.
If your car happens to be a late 76 model, well, you can get it cut out of vinyl and it would be correct.
Mine being a 74, I would just do it in ABS on the 3D printer and be done. Sand it up, paint it with the same paint I used for all my black bits.
But then I debugged my entire car.
I should beef up my tooling with some CNC stuff. That could work also CNC this out of billet and have fun. So many ways to make a badge, I'm guessing it comes down to taste and coin.
$ paint and mask
$ vinyl
$$ ABS 3D printing - or $$$$+$ if you need to buy a 3D printer
$$ - cut up badges, don't for get your time
$$$ 3D printed with molding of a low melting point metal in a casting
$$$ CNC
Finishes will ad cost onto each of these.
Did you by chance check the vendor section, some one might be doing these all ready.
So over on pelican there is
This Guy no affiliation, just a quick find.