Here has been my experience. In the last year, I have made three purchases. Two were tsuba and I paid no tariff using code 970610. My last purchase, a kozuka, was after the first set of tariffs were implemented but then found unlawful. Whatever the new tariff is that was out on all countries, I did have to pay a tariff on this last purchase which is shipping out now. I used the same code that I had used for the tsuba, but this time it was not free.
Jason