For what it's worth, I also got chainplates from Garhauer (they did a great job for a good price), but I didn't oversize. My chainplates had lasted 27 years--another 27 with these new ones will do just fine. Of course, this was not for a PSC, but rather a Sabre.
But my real point is that Garhauer did a great job, and I would recommend them for chainplates.
1984 Sabre 34 Mk I