You found a piece of armour. When you picked it up, bats attacked you.
'The armour you found is a beautiful piece of craftsmanship, ${PLAYER}. What interests me particularly are these gouges in it: look here, and here. I believe this was carried in a creature's claws.
'Attacked by bats? Well, I suppose... but why would a bat carry a piece of armour about? This is most peculiar.
'When inspecting finely crafted armour, there is one dwarf who I would count on beyond all others: Sigdan. Talk to him here in the Chamber of the Cross-roads, he may have some insight into this strange find.'
Sigdan is in the Chamber of the Cross-roads, north of the Dolven-view.
Rambi told you to speak to his friend Sigdan about the armour you found.
Rambi is at the Chamber of the Cross-roads in Durin's Way.
Sigdan has given his evaluation of the scratches in the armour you found.