The first mystery is personal. I used to collect cards by the pack in the late 1970s. I was never able to put together a complete set but I was always close. I remember I never got a 1977 Topps Dave Parker and finally saw his card for the first time when in the late 1980s, I began buying mint complete sets to replace the collections I had. For a while there I did not think Topps was making Jerry Koosman cards. I know for a fact I never got his card in the 1978 set or the 1980 set (through buying packs) and maybe even the 1979 set -even though I had probably had those sets complete to about 98% when they first came out. I did not see these cards until years later when I upgraded my sets.
His Donruss 1982 card was a classic head shot. Jerry had some incredible swings in W-L record in his career.