Lutterloh 1950s Dirndl Supplement

To my knowledge, there's on overall online Lutterloh archive. Also, the company still exists, so they might take a dim view of their patterns being published online in a way that everybody can copy them... if you know which supplement/magazine this pattern was in, you could try if you could find one on Ebay, Etsy or the like. They do turn up, and I have sold a few over the years in my shop, but they're also sought after and can get pricey.
It seems the owner of that Pinterest account uploaded that image, so you could try to contact them.
I've also notice that Lutterloh now features a "vintage collection" on their own website (https://lutterloh-system.de/) and that one features two dirndls (no. 47 and 48) that seem to be from the same supplement/magazine as the pattern you're looking for. So it might be worth contacting them. I don't know if they have a full company archive or not.