All parts are new. Popsicle stick with sandpaper does the trick, and faster than expected. Thanks for the tip as well as confirming which surface to take away from.
Also, and hope it won't lessen their effectiveness, sanded the parkerized (or whatever it is) coating off the top of a few rings by laying flat on a sheet of 400 wet or dry on plate glass. Didn't touch the bottom of rings as presumably the coating will aid in seating against the bottom of piston grooves.
