I just bought a Holland & Holland side lever converted Rook Rifle (converted to .410) in London. The serial number is 102X4 which according to Blue Book is in a missing serial range. However, ser's: 10850 - 10999 are made in 1887. I am estimating mine to be made in 1884 - 1885. The barrel says, WINNERS OF ALL THE FIELD RIFLE TRIALS 1883. It was originally chambered in .295
Question: What does it take to import this gun to the US? If it is over 100 years old, do I still require import paperwork? I will be returning with two other shotguns which required importation permits to the US. I am a US Citizen. Does this fall under "Antique" and not require an import permit? What paperwork do I need at Heathrow for departure and in the US for arrival?
Thanks,
PBF