After try to figure out the best way to motorized the LEGO Lone Ranger Constitution Train 79111 without change the appear of the Train engine. I figured best way is to just simple created the MOC motorized caboose train to push it from the back.
Here Link For Building Instruction
Thank to my Bricklink.com buddy name A Merry Venture for sell me awesome piece to build this setting. I recommend to try his store anytime you place order LEGO part. Here his logo banner from his store site look like this.