I think that type was more common in Europe back in the day, while the Piper ones were more common at US Porsche+Audi dealers, but you had to buy 2 sets for 4 skis.
So you might have some luck finding some on German evil-bay.
Here are some period Porsche or VW-Porsche promo pix & ads with those "OEM Accessory" racks:
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Whereas, the Piper ski racks & Hardt bike racks, & similar competing racks for skis & bikes used the same windshield frame slots & rollbar screw holes, & were sold by the USA P+A dealers back in the 1970's, which looked like these:
Click to view attachment Click to view attachment .
Of course when new, both of mine above were solid stain black paint or anodized finish - as you'll see on the less used & NOS ones which come up for sale occasionally, but mine had some road/air wear over the years of use.
IMHO the above types of ski racks were better than those which attached to the left/driver side rollbar screw holes & the rear bumper tow hook screw hole, both because the latter carried the skis at a 30-45 degree angle offering more wind resistance & noise, as well as blocking access to the rear trunk without removing the skis from the carrier.
Whereas, all of the above types allowed you to open the trunk as far as were the ski tails or tips hung over, plus you could take off the targa top & leave the racks, but then the forward rack wasn't secured into the windshield frame slots.
Good Luck!
Tom
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