Spencer Repeater M 1865 Carbine? HELP

[firefighter317]

Greetings all!  Thank you for this forum and your service to our great Country.

Two Flints I have heard that you are the best with Spencer Firearms.  So hopefully I've come to the proverbial Horse's Mouth.

I have recently acquried this Spencer M1865 Carbine.  I didn't and still do not know much about these firearms. However, I've done some elementary research on the history and purpose.  I am now very interested in finding some more detailed history on this particular weapon. 

This has apparently been part of my family for many years.  Unfortunately, I am now unable to get any word of mouth personal history on it because my step-father, and all of his family who would have known more about it, all have passed away in recent years. 

So to the meat of the conversation. This is an M 1865 Carbine.  It has the Spencer Repeater Rifle Co. Boston Mas. Pat'd Mar 6, 1860 stampted on the top of the receiver.  Also at the breach it has the M 1865 Stamp.  The Serial Stamp is 143XX.  It also has a very interesting srcript "ELA" inside an oval stamped into the left side of the stock.  It stil has the original butt load magazine and overall the weapon is in fairly good shape (just some barrell rust).  I have also found that when the action is opened there is a stapmed "J" in the sliding plates on the right hand side, and a stamped "L" in the left sideof the lever. 
In addition, there are some very distinct etch marks almost like tick marks for counting etched into the top of the sock near the butt.  I am tempted but do not want to speculate on what these may have been count marks for. Maybe you could shed some light. 

Those are the things of this Spencer that most interesed me to this point. 

I hope you can give me some history, and point me in a general direction of more!

Thank you very much,
Firefighter317

[Arizona Trooper]

Finding information on M-1865 and later Spencers is tough. The serial numbers overlap between M-1860s, M-1865s and Burnside contract M-1865s. The ELA cartouche is actually a fancy script ESA for Erskine S Allin, the master armorer at Springfield. Your carbine was rebuilt by Springfield Armory at some point, probably between the late 1860s and early 1870s.