Archeologists automatically see a semi-randomized description of the quality of any mummy wrapping that comes into their inventory (“excellent specimen”, “wretchedly poor”, “slightly damaged”, etc). This gives them a clue as to its enchantment and beatitude.

Wearing a mummy wrapping makes you immune to withering.

If silver dragon scale mail is your only reflection source, or more generally if your only reflection sources come from your shirt and/or body armor, wearing a mummy wrapping over this prevents Medusa from seeing her reflection (though you are still considered to have reflection in all other respects).

Increase the armor delay for mummy wrappings to several turns, because unlike most cloaks you can’t just fasten it quickly.

A magical type of mummy wrapping (or maybe an artifact mummy wrapping) that provides curse resistance when worn.

If a zombie finds a mummy wrapping, it will pick it up and transform into a mummy of that type.

Invisible monsters wearing a mummy wrapping show up as an I (you don’t get to see what they actually are), but an I that moves and doesn’t persist on the map.