All original period buckles in my opinion but close-ups would be good to see detail and markings.
From this pic, I would say they look fine.
From the pics provided I would agree with the guys and say they are all original, better pics would be nice to identify makers etc
BTW the steel Heer buckle is more likely a Gustav Brehmer buckle, have a look for a intertwined GB near and the catch and possibly a date under the roller bar
Ok, thank you for the help!