Riding pants is a US term for any trouser worn for riding whether they be breeches or jodhpurs
Although the trousers for your outfit would not have been worn for riding, they are still called breeches as they are knee length.
Riding breeches of this era, would have had knee patches made of leather (or suede) or matching fabric. Generally, vintage motorcycle, army or sporting (not including horse riding) breeches do not tend to have knee patches HOWEVER, all vintage breeches regardless of use, always fastens with buttons, lacing or rarely, hooks.
When it comes to talking about horse riding trousers, breeches always have knee patches (full seats are a relatively modern invention), and end at knee or calf length as they are always worn with long riding boots. Jodhpurs always have knee patches as well and come down to the ankle so you can wear them with paddock or jodhpur boots.
Hope this helps!
Lei who lives in her manure stained jodhpurs everyday!
