This started out as a challenge to see if I could make a holder for the ImmersionRC PowerPLAY DVR, but I took it too far and ended up with a fully functional replacement holder which looks almost identical, with 3 different back plates for 3 different width FPV goggle straps:
25mm for 1 inch width straps.
38mm for 1.5 inch width straps.
50mm for 2 inch width straps.
If you want a custom width groove for your goggle strap, drop a note in the comments, it only takes a few seconds to adjust the width in the 3D editor.
The front plate prints flat with support turned on for the tabs that clip into the DVR, it took about 50 minutes on my Prusa i3 Mk3 in PLA at 0.2mm layer height, the back plate needs to be printed vertical with no support necessary, took 2.5 hours to print, same PLA at 0.2mm layer height.
You'll need four m2x6 bolts to attach the two pieces together, and to stick some foam onto the back curve, the PowerPLAY should come with 2 spare foam strips.
If you want to design your own back plate to bolt the front plate onto, you'll need to make the 1.9mm diameter bolt holes with these distances from their centers: 74.6mm horizontal, 42.2mm vertical.
I printed mine in PLA, it's just flexible enough to bend the tab back enough to insert/remove the DVR, but PETG would probably be better due it being less brittle and a little more flexible.
UPDATE 21/10/2019: Just 6 days after I created this, ImmersionRC released the .stp file of the original PowerPLAY headstrap clip in the Firmware/Download section: https://www.immersionrc.com/fpv-products/powerplay/
Direct download link: https://www.immersionrc.com/?download=6029