C&R- the individual firearm (not the model- THAT gun right there) is EITHER 50 yrs old or older, in its original configuration, OR it is on the list published by the BATFE- does not need to be both. A 49 yr old Marlin 39A is NOT a C&R- a 50 yr old 39A IS a C&R. A Colt Woodsman or a Winchester Mdl 88 rifle IS a C&R, without regard to age- they are specifically named.
Antique- the firearm in question was made prior to 1-1-1899, OR is a muzzleloader made anytime (that does not readily convert to conventional firearm). Reproductions of pre 1899 guns are also antiques IF they do not use ammo readily available in the US. I could make a series of caliber .30 rimfire revolvers, copying the ones from 1870, and they would be antiques- no .30 rimfire ammo made in over 100 yrs.
An antique is NOT a firearm (see 18 US Code 922). As far as the Feds are concerned, you can put it (unloaded) in the US Mail, and send directly to a buyer in another state. SOME state laws (NY and possibly NJ) do not allow that.