Also kinda confusing to come back to the thread and not find my post. Being I'm a new member I guess I will know I have to search for my post in the future.
With exception of the last sentence in your reply, your questions were off topic, that's why your reply was split, many boards will just delete such replies, I chose to just move it and provide answers, if you stay on topic, your replies won't be moved or deleted.
Concerning the NA frame, that was made in 1986 which does not fall in the years they'll provide service which are 1987 and later, it has nothing to do with being NEF. H&R Inc went bankrupt in 1986, so NA frames were made in the transition time, whether the person you talked to was correct or not, you should find out on the next call. H&R had '96-'99 frames outsourced also, but they'll still fit shotgun barrels to them.
http://www.hr1871.com/Support/accessoryProgram.aspAdditional barrels may be added to firearms of our manufacture since 1987 only, with a serial number that begins with N or H. We do not install additional barrels on any other manufacturer�s firearms.
http://www.gboreloaded.com/forums/index.php/topic,26264.msg503417.html#msg503417Tim