I have just found this rather interesting picture on The British Empire Website of the Officer of the 8th Royal Irish Hussars taken in Ireland in 1870. I agree it is some 20yrs earlier. But you will note that although the Officers are wearing Frock Coats The officer Centre second rear row is wearing the " Cap lines "on the front of the coat even then. Also the Officer Front rank third from Right with his leg crossed is holding a Blackthorn walking stick ( May be another far right.) the remainder appear to be holding sticks or whips.
Colonel Macnaghten sits in the middle of this group for a photo taken in Ireland in 1870. He, like most of the officers wears a blue frock coat and pillbox forage cap. He is the only officer, so dressed, to have rank badges on his coat collar, a crown and star, denoting full colonel according to the 1864 Dress Regulations. The four officers wearing a dress tunic also have rank badges. The seated one on the right is a lieutenant with a crown on a row of gold lace. The gold chain lace on the front of his tunic is not placed in straight lines like the others but curved in the style of some Yeomanry regiments. But he definitely is an 8th Hussar officer because we have a clear view of his sabretache. This item appears to be
Sabretache 1856 although the battle honours are unclear and the shamrock lace is sewn along the top as well as the sides and bottom. His trousers are leather booted, about 8 inches high on the outside, but going up to the knee on the inside.
The officer behind the lieutenant has a star rank badge on his collar but the collar has a row of gold lace and dense braiding which means that he is a major. The elaborate braiding on his cuff also indicates field officer rank, and he has medals for the Crimean War and
Indian Mutiny. The busby is of black sable fur and the white over red plume is supposed to be 8 inches high but looks more like 10 inches. The officer in the middle who wears a forage cap with his dress tunic, is a captain. His rank badges are a crown and star on a collar less braided than the major. His cuff braiding is half visible and consists of small circlets around the edge of the Austrian knot. He has a medal for the Mutiny, and his trousers are unleathered, for dismounted duty. The officer on the left of the photo in dress uniform is also a captain.
The most interesting feature of the photo is the patrol jacket. Careful study of the picture reveals three officers wearing this garment, but there are two styles, neither of which resembles the better known version that was adopted towards the end of the century. Patrol jackets for hussar regiments all had black astrakan fur collars and cuffs but the style of jacket varied from one regiment to another. One of the officers, standing third from the right has black cords plaited across his chest. This style can also be seen (just) on another officer standing at the back, fourth from the left, obscured by two officers in front of him.
But between him and the captain with the medal is an officer wearing the other type of patrol jacket. This has large flat black mohair lace across the chest, somewhat similar to the lace on the frock coats but closer together so that none of the blue coat material shows through. The six falling buttonhole ends are on one side only, corresponding with olivet buttons on the other side. There are cords hanging from the neck which are looped up to the opposite shoulder.
The last type of uniform is stable dress, worn by the officer standing near Macnachten's right shoulder. The waist-length jacket has slim gold braid down the front, along the bottom edge, round top and bottom of the collar, and up the back seams. The cuffs are decorated with small loops of braid. He has leathered trousers and wears no sword belt. The pouch-belt is the same as worn in dress.