i know that dude named Cromwel will forge stuff into stuff, but who makes that human skin armor once i have the skin?

A man appears in Trademeet after you solve the tanner murders in the bridge district. If you have the humanskin and the silver dragon blood and answer his little riddle, he'll make the armour for you. A couple of warnings: after he makes the armour, he attacks you, and the armour itself is pretty woeful.

Totally disgusting concept too. In reality you'd have to be a really sick f#*k to wear it.
Burn it and throw it away.