Klasse 356. Stoddards. NLA. Or any of the vendors like Special Edition, Vintage, or JPS will have them also. What you have to keep in mind is these emblems are made for original cars. The pins are too short to use clips on replicas because the fiberglass is usually too thick. So most people glue them on or drill holes and use silicone or glue instead of clips.
I have two Speedster emblems for sale (they only have two pins because I cut some off to avoid drill too many holes in my car). I may have a 1600 emblem, I'll check. And two Carrera emblems as well, if you're interested.