Iron frame: https://jamesdjulia.com/item/51957-13-397/
Griswold and Gunnison were rather unique among Confederate revolver manufacturers for their ability to actually create a reliable and high quality product and produce it on a regular and predictable schedule. So many of the Confederate revolvers were made by starry-eyed novices, but Griswold & Gunnison ran a proper professional manufacturing operation, and as a result were able to produce as many guns as all other Confederate revolver makers combined.
The Griswold & Gunnison gun was basically a copy of the Colt 3rd model Dragoon, with a 7 1/2 inch .36 caliber barrel, 6-shot cylinder, and brass frame. They have a subtle but recognizable slight rear tilt to the grips, and are virtually all identical, or as close to it as can be expected for hand-fitted guns from the 1860s. In addition, the guns were made with twisted iron cylinders (instead of steel, which was too difficult to procure), and the trusted pattern of the material is often visible on the finished product. The one variation is that at about serial number 1500, the barrel shank changed from rounded to octagonal.
Arvin Gunnison was gunsmith who had been making Colt type revolver in New Orleans before the war, who partnered with Samuel Griswold for the endeavor. Griswold was a very successful entrepreneur who had built Griswoldville on 4,000 acres of land south of Macon, Georgia. There he had a wide variety of businesses, including grist and saw mills, a candle factory, a foundry, and a cotton gin factory. With the assistance of Gunnison, he converted the cotton gin factory into a revolver factory in 1862, and produced about 100 revolvers per month until November of 1864. On the 22nd of that month, Griswoldville was overrun by Union forces and destroyed.