Looking at the Blue Book on these the Model 30 was manufactured 1910 -14. There was also a Field Grade that was made 1913 - 17. It came with a 25'' barrel whereas the other had 26 or 28'' and a
straight stock.
Also had this warning;
During 1998 Marlin issued a service bulletin recommending that the slide action exposed hammer models 1898,16,17,19,19S,19G,19N,21,24,24G,26,30,42,49, and 49N in addition hammerless models 28,31,43,44,53,and 63 should not be fired, as many of these guns 70 to 100 years old, and system failures can and do happen.
Think you may want to just put it on the wall and retire it.