Cycleray questions

[48hdbob1]

I have several versions of the Cycleray headlights in both brass and steel and don't know what versions are for what years. I understand all the brass buckets were chrome from the factory and the steel were painted. Is the earliest type the one with no ground rivet or screw and what years does this light cover? I'm assuming the next type would be the one with the ground rivet near the edge of the bucket by the terminal block. What years would this be correct for? Then there is the type with the ground screw between the mounting stud and the point of the bucket. I've been told this was for later WLA but not sure of this. Have one bucket with Guide in block letters rather than script and saw on one of the posts this is for Hummer. Have several bikes in various stages and I'm trying to sort out this headlight thing, a '40 EL, a '47 FL, and a '48 FL.