>>63836136
>Is it possible for finnish M39's to be antiques and not require an FFL?
Yes. If the receiver was manufactured prior to January 1st, 1899 it is legally an antique.

>>63836266
>I live in Missouri
Then the person you spoke to is wrong. A legal antique can be shipped to your door without issue.

>>63836927
>has to not have been altered
That affects C&R eligibility in the eyes of the ATF, but it doesn't affect antiques.