Just to close out this topic, I found out the following:
- You do indeed have all the parts to build Skarbrand.
- You have the weapon/hand/leg/head options of the regular blood thirster, except for the double handed axe.
However you will need certain parts for the legs/crotch to fit together, so if you want to swap out the legs don't glue this, as you won't be able to use the alternate legs. Also, be careful with the arms because the different weapons attach to different arms.