FYI for Smiths:
1 Rusty Mace + 1 Sharpening Stone = 1 Tarnished Mace.
1 Tarnished Mace + 1 Flask of Water = 1 Small Brick(s) of Ore.
I will pass on more recipes if I find any on other Rusty Weapons.
By the way, Tarnished weapons dont sell for more, but they have a smaller delay between attacks, at least on Stromm in Queynos.