Did you ever find out if the original owner registered it????
Did you get a letter from S&W.???
I dont buy guns as collector items, I like to shoot all my guns, and If I buy an antique like my 1946 M&P I will fire it to get the feel of the old time hand fitting of the action.
If the registered magnum was mine, I would shoot it at the range occaisionally, but since its such a premium collectors item, I would refrain from carrying it. Carry puts too much wear on the pistol's original finish, and if it becomes damaged it could severly reduce the value of it since it is a RARE Collectors item.
If you want to carry a Heavy N-frame .357 magnum revolver, I would look for another model 27 a nice one can be had for $600-800 if its from the 60's, and carry that one instead, that way if it gets taken in a self defense shooting or it gets damaged you are only out a few hundred bucks, instead of a few thousand.
JMHO YMMV