Yes there are still a lot of drawings, I've spent the last 10 years finding and getting them. working on making models from the drawings. These are my copies, he's working with me. It's a very expensive process getting them and I'm trying to find a way to get more people involved so we can get all of them professionally scanned and preserved. As you can see some of them are not in the best shape.
If anyone's interested we can talk on the U-Boat Sim Discord. We've partnered together to make this something beyond just a video game. It's living history that's technically as accurate as possible.
I'm Jonathan on the Discord
https://discord.gg/VcQkGTJI think I've emailed a few of you on this forum a few years ago, Don, and Simon.