1924 Headlights

Unknown

I am not finding a positive way to fasten the ring/glass to the headlight pots. The manual missed headlights altogether!!

The rear rings have 3 small nuts and bolts. The front rings sort of snap on but there is not much "snap"./ I can virtually pull them off by hand or quite easily with a small screwdriver. I was thinking of drilling a small hole at the bottom ( so it can't be seen) and using a self tapping screw for added safety.

Any ideas??

Thanks

Dorien