Mosport,
I can't tell for sure from the photo, but that one appears to have a snap ring around the edge. Maybe it's just reflections of something else. Mine had no snap ring. The outter band was split with two metal 90deg tabs tack welded at the ends. The tabs had a hole in them for a #10 (I think) round head slotted machine screw and nut to tighten the band together. The base was merely a dish with a very slight vertical edge, just enough to capture the bottom domed screen. Then the element layed in there with the top dome screen on top. You had to squeeze it together as you fitted the chrome band around the pieces, then held it together while fiddling with the screw and nut. It wasn't exactly user friendly but it sure was cool looking and of high quality. I always thought of Cal Custom stuff as a little lower quality, mainly their plated stuff, although some of their pieces were done well...(like the valve covers). Just my opinion.
I have a couple very old photos of mine on the car back in '69, but I no longer have the piece itself.
Verne
I sent JoeG an old photo that shows the piece lying on the ground next to the car, but if he posts it, I'll have to kill him..............
