Cool old school light with a great story!
Before modern lights with LEDs, intelligent driver circuits, and multiple output modes, those big multi-D cell Maglites were top shelf in terms of both output and runtime.
Like PN, I now carry a Nitecore that is not much bigger than a mini-Mag, but has five output modes (up to 1800 lumens for a fairly short burst, as low as 1 lumen for about 1000 hours, and three intermediate levels) plus strobe.