Under Federal law, there is a difference between an antique (made before 1 Jan 1899 or not using fixed or available ammo) and a C&R gun (made over 50 years ago as of current date or being listed as a C&R by BATFE). The former, under Federal and most state laws, does not require any paperwork. No 4473, no interstate sales questions. The latter is still a firearm and its C&R status affects only those with C&R licenses. Otherwise, it is subject to all the licensing and transfer requirements imposed on new guns.
State laws may or may not recognize antiques. Some states consider a gun made in 1890 just the same as one made in 2009; others do not.
In any case, the dealer who said that C&R items do not fall under the law may have meant antiques, but the H&R Young American went through several changes, one of which was made until 1941, a C&R but not an Antique.
I understand there is, or is going to be, a book on H&R with production dates, but I don't have it.
BTW, Wincheser 73, what state are you in? Most states don't require registration at all, in some it is voluntary.