I've got to do this myself so I'll be interested in hearing how you manage. I was thinking of engraving mine because I'm a bit nervous about cracking it if I tried stamping. I guess the best thing to do would be to try some test stamping on scrap aluminum first.
Proud restorer and former owner of '94 NAS D90 #590- back in the hands of its original owners.
And now happy owner of a 1988 Swiss-Market D90 Station Wagon.