Other than standard +1 bucklers, this is the only one I can find. There's no piercing or missile protection from bucklers but at least you get a +1 to dexterity with this one. I don't know its location.
Kiels Buckler
This is the buckler of Kiel the Legion-Killer, first-born son of Durlag Trollkiller and Clan-prince of his father's ill-fated tower. Its light weight and excellent craftmanship increase the dexterity of all who bear it by a single point.
STATISTICS:
Armor Class Bonus: 1
Special: No Missile/Piercing Attack Protection
Special: +1 Dexterity while equipped
Weight: 2
Requires: 4 Strength
Unusable By:
Mage
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It's bleedin dark down here, slippery too.
Man, that's a pisser.