Welcome, Frank! It is nice to have you join us. You have a great car and I am sorry to hear you had trouble with 15 inch Magnums. It looks like you already have the Torque Thrust wheels, and they look great, but if you like the look of the original Magnums you should also consider the American Racing VN501. They are aluminum and come in a variety of sizes. I went with 17x7 when I did the upgrade to disc brakes on my car and they are working out great for me. Just another option to consider.
Again, welcome aboard. I have passed through Stuttgart several times but have not spent much time there. My dad was in the USAF and stationed in Frankfurt when I was born but dad got transferred home shortly after so I was just a baby and don't remember anything. However, after my dad passed away my mother went back to work at Rhine-Mein AFB. She lived just south of the airbase/airport in Langen from 1986 until she retired in 1993. I made several trips over to visit while she was there also got the opportunity to work in Frankfurt and Dusseldorf for 5 weeks back in 1990 (I worked for PepsiCo back then). It was an interesting time and I am forever grateful for the experience. Having visited on vacation several times in the late 80s before the Wall came down and then being able to go back for 5 weeks shortly after the Wall came down was really something to see.