It has been a long while, but I am pretty positive when I was doing my TRP purchase research, that everything I read said frames=Brazil. Maybe if they are unfinished there is (or was) no requirement to make a separate mention and they were able to just throw the "made in USA" stamp on them.
Springfield Armory had a contract with Imbel of Brazil. Until some time around 2010 ALL Springfield 1911 frames and slides came from Imbel. The lower-end pistols were completely assembled in Brazil and were marked "Made in Brazil." The fine print of the law allowed Springfield to import the parts for the higher end guns from Brazil, assemble them in the U.S., and legally mark them as "Made in USA."
Since approximately 2010 that arrangement is no longer in effect. I don't think Springfield sources any 1911 parts or guns from Brazil now.