Two-trigger Frank Wesson "First type", as per photo, aprox 2000 made C1859 to 1863 or 64. Cal 22, 32, 38 & 44 rimfire. Majority were iron frame although there were some brass frame sporting models. Available as Sporter or Military Carbine. Military was 44 rimfire with 24" barrel.
Kitteridge & Co supplied 151 Military Carbines to the U.S. Government shortly after Gettysburg in July 1863.
Sorry don't know how much they weighed.