Looks like standard side mountings so quiet sure it will fit any available side mounted passenger car seat. They are stating 450mm width at the rig and 445mm at the seat. So pretty sure everything from 400mm to 500mm can fit with little adjustments. If not directly just use washers or better widen the lower L-bracket holes connecting to the slider if they aren't like this from the factory. Normally done at L-brackets for cars to fit every seat and have wiggle room fitting them to the car.
I emailed the American store last week looking for advice/options, haven’t got a response either.
I just found the EU store sells the leather covers. I’d consider that instead of replacing the entire seat but need to find if the EU store will ship to the U.S.