OP, Hopefully you'll be able to turn this into, "A Challenging", "But Valuable", "Growth Opportunity"......Yeah, I Know, right?, it STILL SUCKS.

The "exploded" diagram from Sheldon's website in your previous post is for an Old-School THREADED HEADSET. This is of *Some Concern* to me.
You state in the first post that your Bikes Direct "Mercier" was equipped with a "THREADLESS HEADSET"? (Google image search shows the TT Pro with THREADLESS HEADSET as well). Starting with the PROPER DIAGRAMS will save a LOT of wasted TIME, and MONEY, should you decide to DIY. Assuming you are comfortable and have EXPERIENCE with some what more advanced maintenance of your machines.
I would also strongly recommend having a TRUSTED LBS mechanic go over the bike, plus all the parts You were able to collect from the scene of the crime and give you a quote for parts and labor. Many shops will do this for a nominal fee at most, in my experience.