Antique Cane Back Armchair - Different Period Elements?

This chair appears to have no alterations. The nails are fairly small, match in color(rusty or copper colored) and shape.
The chair is short and I cannot find any evidence that it used to have applied feet. Measures 85cm at from the floor to the top of the back.
The seat is removable(but not to easily), made of velvet (blue and gold color), has some type of metal support and is stuffed with straw and horse hair. There appears to have originally been some type of label on the bottom.
Frame is solid and handmade. Cane back. Has under arm splats or decoration. They are inserted via notches under both arms and on the bottom of the seat rail.
Construction- Mortise & tenon and/or dowels. No screws, that I can see. The cleats under the seat rail are open, unfinished and rough. The underside seat rail and most of the underside is rough/unfinished. Has white chalk marks on two places, front and back,on the underside of the rail.