Snaffle / Halter / Trense Holder for 20mm diameter holes in 40mm grid

I designed this piece for a friend who wanted to have a holder for horse-stuff in her locker without drilling holes in the locker door. I accepted the challenge and it worked out fine. :)

Her locker door has a grid of 20mm diameter holes with a center to center distance of 40mm horizontally and 35mm vertically. I don't know the make and model. The hooks are 80mm apart (center to center) and should fit a 17mm hole.