If I had to guess, I'd go with one of these three pre-Magnum matches:
Boesch @ Houston, TX - Sam Houston Coliseum - July 31, 1981 Tom Prichard vs Terry Allen
Boesch @ Houston, TX – Sam Houston Coliseum – August 7, 1981
The Spoiler vs Terry Allen (How cool does that sound?)
Boesch @ Houston, TX - Sam Houston Coliseum - September 4, 1981
Buck Robley vs Terry Allen
OR, maybe this one:
Boesch @ Houston, TX – Sam Houston Coliseum – October 7, 1983
Magnum TA & Lone Eagle vs Tom Stanton & Cowboy Lang
Those are my guesses. There are some other fun oddities I can't wait to see eventually (like a cage match with Ladd, and a match with Bundy, and a series with Rip Rogers, and one match with Flair and a late match with the Baron), but that's what I'm going with.