Naturally, in order to unseal, you'll need the regular item.
This, I will do for free...
As you probably know, the unsealed gloves and boots will give you a set bonus.
Only gloves and boots of identical grade may be combined.
I am only able to work on B grade.
If you wish to unseal items of a higher grade, you'll need to talk to the Blacksmith of Mammon...
You probably already knew all of this...
Select the item that you wish to unseal from the list...
View list:

Unseal Gloves | Unseal Boots