Paladin Barett

„

Interesting... I'll take this, thanks for your efforts, Since you're not a Brotherhood member, i cannot give you any rewards, but you have our sincere thanks.

”

That's nice way of saying "Fuck you". As you can see currently item called: Brotherhood Dog Tags is useless. Bringing it to Knight Matthews will results in obtaining 500 experience points...and thats it. So for now better keep it as it looks like quest is currently blocked altogether with Broterhood of Steel faction.