Mosin-Nagant 91/30 - are some of these "non-guns"? (I would think so, since 1891 precedes 1898).
Are you sure that its just the date on the reciever that matters? I know that a rifle will no longer qualify as a C&R if its been "modufied". I cant imagine ANY 91/30 or M44 qualifying as a non-gun regardless of when the reciever dates to.