I did find some information on this issue but the person who mentioned this issue didn't reveal how they solved it, only posted that they solved it.
My issue is this: I have a Human and I got some cool CAST parts from the mission pass and a couple from scratch tickets and I thought "Oh, I'll just save these until I make a CAST. I stored the body/arm/leg parts no problem and can equip them on a CAST I just made. However, I did consume the Head Part tickets on my human before I made my CAST. I did this with the understanding that this would unlock the parts on the account. After all, why would I be allowed to consume a CAST Head Part ticket on a Human unless it was an account unlock?
However, I made my CAST. I went to the Salon and I went to Fashion and neither location has an option for me to select these unlock head parts. Did I just waste these items by unlocking them on a Human? I can see in the Fashion section that there is an option for switching head parts but none of the parts I unlocked on the Human are there.
So, am I missing something or did I screw up and basically throw away cool CAST parts?
EDIT: I guess I answered my own question. I have a CAST auxiliary that is able to equip the head parts I unlocked so they are not account-wide. I can make an interesting looking auxiliary but not the really cool CAST character I had in mind. FML. Why are those head part tickets not account-wide unlocks?