Your rifle was made by little known maker, John G. Phillips, who moved around and worked in several states. When you post good pictures of the rifle, we'll be able to determine its age, and then we'll know which state it was made in. Please check the signature's middle initial again when you look at the gun. You reported a "C" but it should be a "G," so we know we have the right man.
The Maslin lock is a commercial lock sold through hardware stores in numerous states, where gunsmiths could pick up parts and supplies, often including barrels.
When you get a chance to take better pictures, would you please try to get the following views of the gun, taken straight down over gun and not at an angle. If you can lay gun on a light, neutral background [light grays, greens, blues, concrete driveway, etc. are best] your pictures will show details better.
1. front half-shot showing full butt out to about 10" past lock plate,
2. rear half-shot showing full butt out to about 10" past where lock plate sits on other side,
3. full length view of front side of gun showing complete gun,
4. picture of barrel signature.
Also like to know barrel length and bore size [measure bore with ruler to closest 1/16th of an inch].
Shelby Gallien