Kyle

The buckles you see on ebay are for what I believe are called Guards Pattern buckled brogues. The larger of the buckles fits on to the toe of the shoe just like a belt buckle. These brogues which are manufactured by a company called Sanders based in Northhampton a centre for shoe making in the UK. They are normally only available to the military and occasionally appear on ebay without buckles. My understanding is that the buckles are manufactured by Dalman and Narborough who are based in Birmingham UK

It looks very much as though the buckles worn by Jim Motherwell in your photograph are the same type as advertised on ebay and that he is wearing Guards Pattern brogues

What you call the bar and buckle brogues are now also used by the military but the front buckle in those models is a "false" buckle and decorative only

In my view the Guards Pattern brogues are much more impressive.