He had a decent little feud with Crusher Blackwell in 81 that I thought would push him to the next level, but he really didn't do much in the immediate afterburn of that feud. His tv match with Bockwinkel in 83 and subsequent title match in St. Paul were decent, but not the kind that would elevate him to the status of being a legit draw.
The Blackwell feud, for example, ended with Hogan making the save in their blowoff after Brad beat Blackwell. This segued into Blackwell-Hogan matches. Fast forward to Rheingans-Zurkov around 85-86, and Rheingans gets saved from Zurkov by Sgt. Slaughter.
Rheingans never really did the saving and sort of got left to fend for himself a lot. Funny enough, he would probably have had a decent series with Hennig in 87-88 but it was right around then that Vince picked him up to be a JTTS-type for several months. By that point it really was too late for Brad to get to the next level, and given the pay in the AWA was quite low at that point, the jump was all about money.
Brad did come back when Vince was done with him. Verne was in no position to hold a grudge by then.