hope they changed the clear plastic ,, my bigger map case bought in the 90's rotted rather fast to shards..

Now, I'd just get one from a boat shop instead.. a nav chart cover.
I got Bigger Maps. so I didn't have to refold them as often. draped it over a front rack load over the wheel.

but you wanted it to fit the generation6 bag.;.

older bags used a common snap ... now that is a proprietary cleat to hold a cord over it seems