This is a GOOD to NEAR VERY GOOD example of the combination tool issued for use with the 2nd Model Maynardpercussion breechloading carbine. These tools are pictured and described on page 181 of Gun Tools: Their History and Identification, Volume I by Shaffer, Rutledge, and Dorsey. There they show the evolution of the Massachusetts Arms Company made tools for the Maynard rifle and carbine, with this pattern being the Civil War era percussion tool. Two additional variants are pictured which are for the later, post-war cartridge variants of those long arms. The tool has an overall length of 3.58” including the box end cone wrench and also has a 2.30” long pivoting arm. The ends of both arms are flat head screwdrivers, while the box end wrench was designed to remove the percussion cone from the carbine and to install replacement cones. The internal measurement of the cone wench is 0.25” which is correct for the shoulders of the Maynard percussion cone, while the nearly identical tool made by Massachusetts Arms Company for the Smith Carbine has a slightly larger socket to accommodate the shoulders of the standard sized US musket cone.
The tool is a nice solid example that retains about 30% of its original blued finish, with the balance fading to a dull gray with some pitting around the neck of the tool. The box end cone drive wrench is in good condition without damage, and the two screwdriver blades are in good condition as well and the smaller pivoting arm still moves as it should. Overall, this is a solid example of a relatively scarce Civil War carbine tool to add to your carbine collection or display.
Please note that the images are much larger than the actual tool is! This allows you to see condition and details easily.