Would anyone have a picture of the back of the ashtray showing the stop that is attached to the back? The one I have has broken piece of what appears to be spring steel. I am not sure if it is straight, curved or has some type of catch that hits the dimple in the ashtray frame. Any measurements will be appreciated also.

 

Sorry for the out of focus picture, but you get the idea. You're right, it is a spring that is riveted to the rear of the ashtray center.

 

Thanks for the picture. I will be able to fabricate it.

 

It's got a cross-shaped hole in the depression wherein one could snuff out whatever they happened to be smoking.
It is a rare bird who can temper their own spring steel these days. I do some black smithing from time to time.