In “To Cut a Regency Coat”, Suzi Clarke, a British costumer, goes into great detail on how to make this man’s Regency garment.
The basic man’s coat for the first twenty-five years of the 19th century changed very little. It was cut to fit very firmly across the shoulders, with a shoulder seam that sloped into the back armscye. There was a center back seam, and the side seams curved toward the center back from the same armscye, narrowing in towards the waist. The center back continued on into the skirt, although occasionally there was a waist seam. The two front skirts were cut in one piece with the body, usually with a “fish” or dart at waist level early in the century.
All these coats were beautifully cut and sewn together, the stitching being very neat and small. English tailoring at this time was the envy of the fashionable world, and these coats were of the time of the famous George “Beau” Brummell. The top coat belonged to a banker, Mr. Coutts, and was made by the famous tailor, “Weston” of Savile Row, mentioned in Georgette Heyer, and possibly Jane Austen. It was lodged at Coutts Bank, together with other items of clothing, in 1805, and donated to the Museum of London many years later.