Dunstan can repair degradable armours such as Barrows equipment and Ancient armour for the player at a price. The equipment does not need to be fully degraded in order to have it repaired. The cost of any repair is proportional to how degraded the item is. Alternatively, players can repair the armours at a cheaper price themselves at an armour stand in any player-owned house.
Saint Dunstan is the patron saint of blacksmiths, as he was a smith who worked for the church.
For a few weeks after the update of the law talisman, every town crier in the cities of Draynor, Falador and Ardougne would say: "Hear ye! Dunstan has new rewards for those who helped his son!"
If a player had completed the Troll Stronghold quest before the update of the law talisman, upon logging on, a message in the chat box would say, "Why not stop by Dunstan's house in Burthorpe? The smithy has a special reward for you." This reward is two 10,000 experience lamps, which can only be used on skills level 30+.
After Dunstan makes a sled for you in the Troll Romance quest, he says "Thank you, come again", which could be a reference to Apu from The Simpsons.