Turned these up on the lathe, any durable plastic will do, I used nylon. The dimensions are, from the screw head end:
.600 for.250
.815 for.090
.950 for.090
.650 for.250

Drill .328 hole, insert 10-24 coupling nut, use two 10-24x3/8 screws.

Use the original locking clip on the inside of the light