My pistons arrived from Nissan Comp the other day. I was told they were NLA, but some stock was found. Now I can rebuild both sets of calipers. I did aquire a spare set of Sumitomos from a racer in Texas who has moved on th Hondas. I found him thru an ad I placed on an SCCA production car forum. I have a set of vented rotor calipers on one car, and solid rotor calipers on the other. I'll have to investigate my rotor options, maybe switching one car to the solid rotor version. The solid disc part # may be written down, um, somewhere, in my car's notebooks.