I sized up the pads that came out of the fa18 package with the fa171's that they sent for the front and the two sets seem to match up identical...so more than likely these were mis-packaged. In retrospect I remember thinking how the rears and the fronts looked like the same size when I took them out of the box, but this is the first time I've done brake work on this bike so I didn't think anything of it at the time.
I don't have access to a grinder, and there is NOTHING open or available to machine them, AND 4mm is a f*ckload of material to file by hand, so I'll need to drop the old pads back in and push the caliper pistons out gently to where they were before I pressed them back for the installation of the new ones.
The lowest side of the old material measures about 2mm remaining thickness so I will hopefully be ok till I get back to civilization after the holiday and order some different new ones.
Foiled by the manufacturer!
At least I got the oil changed and I'm gonna do a brake flush.
Thanks all for your input!