Here's the split version of the Captain America shield, with the added handle file:

8 different Outer Ring Files, an Inner Circle, and a handle file that can be used for both sides.

Each handle mount file should work with straps ~ 1.5 inches in width.

Modeled to be comic accurate in size (meaning 2.5 feet in diameter). Scale to 86% for 26 inches in diameter (much more reasonable).