The only antique replica in airsoft from what I know is KTW Flintlock
UPDATE FROM THE FAQ
Okay, so I canít import guns. What about parts and accessories?
Yes. The good news is that most parts and accessories, including most magazines, can be successfully imported by individuals without requiring a BFL.
Examples of things you CANNOT import:
* Frames, receivers, and metal bodies
* Shell Magazine capable of holding live rounds with capacity over 5 rounds in centerfire or 10 rounds for pistol magazine
* Airsoft guns that has muzzle velocity of less than 430fps with 0.2g bb and muzzle velocity greater than 840fps with 0.2g bb.
Examples of things you CAN import but will almost guarantee result in holdup of parcel in custom:
* Hand and 40mm grenades that look real
* Suppressors and silencers
* Prohibited-length outer handgun barrels (i.e. USP Compact, Glock 26)
* AEG magazines with fake cartridges (i.e. P90, G36, SG 552 mags)
* Airsoft gun that are capable of shooting 430fps with 0.2g bb but does not shoot over 840fps with 0.2g bb
* Handgun slides
Examples of things you CAN import:
* Magazines for AEGs and GBBs without fake cartridges
* Outer barrels for most guns
* Inner barrels of any type
* Flash suppressors
* Scopes, red dot sights, iron sights, lasers
* Rail systems and scope mounts
* Springs, bushings, gears, pistons, or other gearbox parts
* Batteries, BBs, loading tools
* Helmets, goggles, body armor, tactical vests, camouflage
NOTE: Possession of body armor in Province of British Colombia is illegal without proper permit.
Examples of Item that is illegal to EXPORT from United States of America without license includes:
* Firearm parts exceed over $100 in value
* Firearm (and parts) that have not pre-approved by the DOD
* Body Armor with NIJ Level III or Level IV (Plate carrier who does not have that capability during export is acceptable)
* Ammunition for centerfire/rimfire firearm (even for dummy rounds)