Since a similar thread is still running (and not wanting to hijack), I will post a picture here of my 6520. The searchlight on this car in no way matches anything I have seen prewar or postwar, and is almost certainly not original to this car. So what is it?
The only visual reference I have found was on ebay where a lad is selling his nearly identical searchlight case and labeling it as Standard Gauge.
The case has grooves, as you can see, and I do have a snap ring that fits perfectly, but no lens (the 6520-11 is the wrong design and is way too small of a diameter.)
Can anyone help ID this searchlight case? 
