686man, since no factory records are presently known for the Lefever Arms Co., you can only hope for an approximate age based on the serial number and characteristics of the gun. Even then, Lefevers were often assembled years after the individual parts were manufactured. For instance, I once had a Lefever G ejector gun in 16 ga. that should have been produced about 1892ish according to the serial number. However the gun bore a patent date of 1907!
You'll be able to learn a lot more about your Lefever at the Lefever Forum,
http://lefeverforum.informe.com .
