[Fate]

At first it does sound scary, but it seems to me that a stealth body-slot item could even be construction 6 and be balanced (then again, I'm a bad SP player).

Here is a stealth item that might be interesting:

Cloak of the Unknown - Construction 2 or 4, something like 1N 1D, Cursed, Causes the wearer to receive automatic feeble mindedness and (maybe?) gives a slight chance the commander will be lost forever. To stop SC's from using it just give -5 MR.

Armour slot, protection 0, defense 0, encumbrance 0.

On the plus side it gives stealth 0 to the commander and up to 10 troops under his/her command.

Another possibility:

Unique Artifact - Sword of Darkness. Maybe 4 or 5 D? 2 hand slots. Cursed, ! automatic Darkness in battle !, blindess on hit? and gives 10 or 20 stealth, and -5 MR again. Att 0, Def 0, Dmg 10, Len 3.

I think the fact this weapon is more or less limited to those with dark vision makes it limited usage.