Well after over 10 years of searching, I finally found a 521 to call my own.
Last fall I saw a guy with a ‘71 521 on a trailer, he had just bought it at action for dirt cheap. He had plans for it, but he gave me his business card so I could send him my contact information. A couple days ago I decided to inquire about the truck, well he’s moving and renovating and needs to downsize his car collection 🥳. I made arrangements to buy the truck and to get it to it’s new home. It’ll be a couple weeks till I have it at my place so unfortunately no pics yet.