Question: The TT pistol was developed as a replacement for the gas-seal revolver produced by whom?
Sentence (from "Colt Pocket Percussion Revolvers"): It is a smaller brother of the more famous "Colt's Revolving Belt Pistol of Naval Caliber" introduced the same year and commonly designated by collectors as the "1851 Navy Model" (and which was a basically a larger, .36 caliber of the Pocket Model, "belt pistol" referring to a weapon sized to fit into a belt holster, as opposed to the saddle holsters generally called for by Colt's larger cavalry combat models).
Relevant evidence: No