Again, welcome. The barrel stamping is actually CTG (for cartridge), not OTG. Before model numbers were introduced, your gun was called the .22 Combat Masterpiece. The word "combat" doesn't imply a purpose, but is merely a shorthand term for four-inch barrel with ramp front sight. That configuration will clear a holster more quickly and smoothly in case the gun needs to be produced in a hurry.
Even in worn and scratched condition the four-inch K-22s will bring $450 or so. In better shape, as I take yours to be, it should probably be valued at $500 or a little more. If you were conservative in reporting its condition, it could sell for $600. These fine '50s era revolvers are much in demand. Collector grade guns, new or almost new in the box with all tools and papers, sell for serious money.
Feel free to post pics. We like looking at guns here, and it will help us narrow the value spread on yours.