OK great, thanks Tony once again.
In other news (and the original reason why I posted), I now also think the medal/white ribbon is a faded 10 Year Anniversary of Independence, and the badge on his right shoulder is the Equestrian Złoty Wielka. Thankfully I had a high enough resolution scan of the aforementioned photo, so I went a little CSI and took a closer look.
If you look closely it looks like there is a suggestion of Piłsudski's face.
I had read that this decoration was issued in 1928 to those with 5years service or more. AJR would have been at Cavalry Officer's School in Grudziadz, so I guess they would have counted time at Kadet Korps? Does that sound right?