I have three ACR 4F strobe lights, an old (80's or so strobe light) that have been modified to run on two CR123A batteries instead of the original equipment mercury battery. I note that my recent flashlight acquisitions running a 18650 battery can also accept two CR123s. So, is it possible to stuff a 18650 into the 4F and operate it properly? Or will the whole thing melt down?

I suppose I could just try it, but, as always, I am extremely prudent and seek expert advice....