In essence, those ends are clips, they're as easy to attach and remove from the body as any other "clip" sort of device.
Just have them permanently attached to whatever strap you'd like. If you don't want to attach them permanently, you can use a small loop of narrow webbing with a buckle in it to be an intermediate piece between the clips and the strap. Sort of like the leather portion of the strap you've pictured. There are many straps made this way.
This was something I was going to do for a long time, but I couldn't find a Hasselblad strap that was suitably cheap to harvest the ends off of. I ended up getting a Hasselblad medium width web strap.