1864 Colt musket

I recently purchased an 1864 colt musket and having trouble deciphering some of the stamps on the stock. Above the trigger guard there's AHM stamped in the wood with an LJ stamped nearby. Near the stock plate there's the number 24 stamped in the wood with an E.M.W. Stamped just above the U.S marking. I know some of the various single letter stamps are inspector's markings and impossible to trace but I haven't seen anything like this yet. I am new to collecting and wanted to seek some advice. Thanks in advance for your help.