There was a players strike in 1981 leading to an extra round of playoffs and the Astros lost to the Dodgers in the first round so these tickets should have been sent in for a refund. There are 4 sets of tickets and the original letter and refund information included.

Stored in original envelope all these years so condition is outstanding. 

A cool conversation piece, I can see these being framed for the Astros fan who has everything.