I remember an article in Dragon Magazine back in the mid 80s. It was about weapon damage by class. All classes could use all weapons, but not all classes could use them effectively.
If the magic-user picks up a long sword, he'd still be limited to d4 damage. Actually, he was limited to d4 damage in all but staff (d6.)
Clerics and thieves were limited to d6 damage and fighters could hit d8 or d10 depending on the weapon.
It solved the problem of the character that wants to wield a long sword like Gandalf without putting long sword damage potential in the wizard's hands.
I never used the variant rule, but it appeals to me these days and I may just introduce it in a future campaign.
Have you ever used class based weapon damage or something similar in your campaigns?