You will never know, or be able to determine how many 16-bore E Grade Lefever guns were manufactured, as the original production/shipping records simply do not exist; and the numbers of guns estimated for any production year are nothing more than best "guesstimate" type projections. And not only must you contend with that reality, Lefever did not build guns in sequential order; so examples with a serial number in the 30XXX range may have in fact been built late in production, or even finished by Ithaca after Ithaca purchased the Lefever Arms Company in 1915. The E Grade Lefever was Lefever's most popular mid-grade gun and carried a catalog price of $100; as Lefever offered several higher, and more costly grades above the E Grade beginning with the D, C, B, A, AA, Optimus, and the $1000 dollar grade. If this gun is truly in 95% condition, it should not be hunted with; and should certainly not be fired with modern shells, as it was not designed to consistently handle modern high pressure loads (even "light" modern loads generate high pressures, as they are loaded to high pressures to insure their function in a spring loaded semi-auto). Also, as a poster has noted, unless your chambers have been lengthened; they are bored shorter than today's 2 3/4" standard. If you want to shoot this gun anyway, several makers load low pressure, proper length "vintager" loads designed for vintage double guns (Gamebore, RST, Polywad, etc); or you can hand load using recipes generating pressures of 8,000PSI or less.