I enjoyed reading your thoughts on this as well as so many others. Thanks for taking the time to post it. My primary need will be snow…so far we’ve got nothing. My Chevy pickup may be the best option
I wanted to add that Eaton - as of their November 2023 catalog - now makes a front ELocker for '69-'99 40, 60, and 70 series 9.5" differentials. I would think they're the same as the Harrop offerings but from a US supply chain. Model number 14212-1. It will also work in the rear of any full float rear ends. I didn't know this when I posted above.
I plan to pull the trigger on an Auburn in the rear as soon as I can spare the cash (may be a while). Some left foot braking to trick the LSD may have gotten me unstuck a couple of winters back when the day warmed up and the snow turned to Squishee. I posted a pic in the "What have you done to your Cruiser" thread but I can't seem to find it. Someone pointed out that chains would've worked well and might have kept me from slipping into the ditch.
If you're really concerned about an Auburn (or autolocker/lunchbox) in the rear then I would opt for a rear ARB. You'd have an open diff for most driving and the locker to get you unstuck when/if you need it.