OSR really seems like a goldmine of procedurally generation mechanics, if you find the right actual olay context for them. I've found myself "friends" with some old exTSR spags on FB and they've got their own house rules. Frank Mentzer literally eyeballs a dicepool and odds in his head whenever a player fires a missile weapon into a melee, but its a consistent feature of his dungeon gaming for the last 40 years so players can trust that consistency.