that sounds pretty big, and no doubt you've looked yourself and not found anything. could you make your own, by mounting a standard a/nut on a small piece of sheet ?
Hmmm, .688 MAX pitch for an MS21059? I've pitched them quite a bit farther after pryng them out of some unreachable area of an aircraft and being rewarded with a couple of bloody knuckles.>:-<
you'd attach the nutplates (maybe the one-legged variety) onto a strip of sheet stock, and attach that "somehow" to the plane ... no stretch marks involved
I prefer cutting-out and using a 1-nut section of a gang-channel nutplate. ED should probably be at least 0.2... so overal length is ~1.16"(+) [0.58" X 2].