Anonymity Hood
Or perhaps you can make a new thief, transmute the helm onto another low level helm, put the newly transmuted helm in your bank. Now logon to your level 80 and transmute the helm in your bank to the helm you’d like to use.
Yes, transmutation stones should work.
You get 3 of them each time you clear a map, or you can buy them with gems.
Your bank is shared between characters, so you can just put a white helm of any type in your bank, make a new thief and run to the bank, then transmute the starting helm with that one to get the appearance back to your 80 thf.
You can indeed transmute these across characters. I’ve seen Rangers and Engineers also using our hoods or Engineer goggles.
Acquire a Transmute Stone.
Roll a new Thief.
Complete the tutorial and run to a bank.
Deposit your Hood/Headband/Mask.
Get back on your other character.
Purchase a…oh, let’s say the generic Medium Mask every vendor sells.
Transmute the starter item and mask. Make sure you select the item first, then the mask’s stats.
It will say soulbound, but it’s not. You can freely move them around as long as this item is a non-soulbound item level (White or Blue). Once it’s on a Masterwork or higher, I believe it’s stuck.