Is the rifle's barrel signed or initialed? From what I see in your posted photos, while it may be an Earnest, it has some details that don't seem consistent with Jacob's work; 1) side facings with flattened rear end, 2) patchbox hinge that extends across the full width of patchbox instead of just across the lid, 3) patchbox engraving that seems less polished than Jacob Earnst's work; single trigger and larger flattened area at base of cheekpiece.
Again, you may have a late Jacob Earnest rifle where he modified some of his earlier details. However, it would be worth checking the source listed on the tag to see what rifle they are basing their attribution on, to make sure it's a solid attribution.
Shelby Gallien