Sorry, I had forgotten about this. I just looked on mine and the handle and threads seem to be one piece. My guess is that the threads had broken off the handle and were still inside the end cap. So the previous owner tossed the end cap with the threaded part still inside it. That pretty much makes the light useless.
I think I do have another handle light in the shed, but it already has a future home. I sold one a year or two ago and just don't have a spare that I am willing to let go of right now. Keep your eyes on CL and FB MP and also Ebay. They do pop up once in a while. They also get sold with grills for really cheap or even free curb alert grills. One thing I have come to learn with rehabbing grills. That is that you just have to be patient and eventually you will find that unicorn you have been looking for for a reasonable price. Another thing that I have learned is that it seems like once you find that unicorn, they tend to run in herds.