Just received my first batch of custom stamped box wrenches for Seymour snaths (all current models.) The large end is sized for the nut of the loop bolt and the small end is sized for the retaining bolt of the heel plate. Nice and flat so it slips in a pocket unobtrusively, and made for us in the USA out of plated, heat treated steel. They'll only be about $1.50 and I'll be getting them up on the site tomorrow if things go to plan. Wish I had one of these things years ago--it would have made field adjustments a lot easier than carrying around a typical wrench.
Back in the day, snath manufacturers used to include small cast iron box wrenches with their snaths. These are a nice modern analog!