wtmr, you are a lucky fellow!

Your 27 CFR 478.113a document is quite clear on importation of barrels.

27 CFR 478.113a - Importation of firearm barrels by nonlicensees. | US Law | LII / Legal Information Institute

Although, I guess a law is only as good as being enforced.

Seems a little unfair, as these barrels were made in the US, and being of historical significance.

Ted