If my character has a piece of gear, say partial hardened leather, and he wants to improve it with an upgrade, say fitted, how much would this cost and how long would it take? I don't know if upgrading old gear is in the rules and I've missed it, or if it's not really addressed. Some help would be appreciated.
The closest is that the Craft skill has "Build or Improve Object". Unfortunately, it doesn't have specific rules for upgrading items, so I'll share my thoughts.
I'd charge coin equal to the upgrade cost (100s + 200% = 200s charged) and time based on the item (Hardened Leather is W, so at least a week). It would require a complexity allowance of 15 (Skill bonus + career level + feat modifications), and the modifier's skill check would determine precisely how long it takes (again - minimum of 1 week).