Thank you so much, BlackSheep! Now that I know what it is, and since it will be covered in canvas, I am thinking about using a Sharpie marker cap mated to an Itoya Calligraphy marker cap, adding the side bulges which in the photo received special “ear covers” if you think of the searchlight as a face...
M48 Reference: I owe some fella whose handle is Frenchie over at Armorama for posting these online:
You can see the “ears” clearly and best of all the mounting points! I know the mounting points to the tank vary based on the model’s design but the framing is the same.
Planning surgery:
Although for the K.I.S.S. Method, I may simply use the Sharpie cap, drill out openings, fill the back, add the wiring harness then drape a thin piece of Milliput over everything.