Yes, the Chapter 3 items are enhancements of the Chapter 1 items. Really, though, from what I've seen they aren't all that spectacular enhancements. Check the Toolkit, make a module, and bring up the list of weapons. The craftable items will all be listed twice, one will be +1 and another listing will have it as +2 or +3, for example. The +2/+3 versions will be available in Chapter 3.

Pet Peeve: Whitebone armor. I go use 5 smuggler's coins to get leather +1, I get the gargoyle skull, I make the armor...and it's a bloody suit of half-plate. While this is handy to know for future reference (next time I play a fighter/cleric/paladin type) it doesn't do my poor ranger a damn bit of good.