A little production data on the "New Line" revolvers from Wilson's Book of Colt Firearms-
New Line .22RF c.1873-1877 aprox.55,343 made. Marketed through c.1890
New Line .30RF c.1874-1876 aprox.11,000 made
New Line .32 RF&CF c.1873-1884 aprox.22,000 made
New Line .38 RF&CF c.1874-1880 aprox.5500 made
New Line .41RF&CF c.1874-1879 aprox.7000 made
These were eventually replaced by the "New House" and "New Police" models.