Archeologists see value indicators on weapons and armor that are not fully identified to get a vague idea of what they are. Examples given are “an extraordinary [weapon]” for a +4 weapon or “an average [weapon]” for a +0 weapon. At higher experience levels they may be able to identify the exact enchantment automatically. This is flavored as appraising the age and quality of antiques.

A slightly different implementation may make it non-guaranteed to see this, with the odds dependent partly on experience level but also on intelligence and luck.

A third proposal is that it doesn’t happen automatically, but they can get this indicator or identify the enchantment of a weapon by rubbing their touchstone on it.

Touchstones can generate in hardware stores.

Artifact unaligned touchstone called Grinder: rubbing it on or applying it to an object repairs one level of rust or corrosion but decreases enchantment by 1 (which can go negative). Invoking it cancels a single object.

YAFM for when polymorphed into a glass golem and you rub a touchstone against “-“.

Gnomes spawned with a sufficiently high starting level, or else just a fixed percentage of gnome lords and a different fixed percentage of gnome kings, generate with a touchstone.

Touchstones no longer count as magical items. (Real-life touchstones aren’t.)

Increase the damage of slung touchstones. Thrown luckstones retain their lowish damage but have a chance of getting “lucky” hits that do much more damage or instakill monsters.