It seems there was a PLV30 Kirby Lauson fitted to the 8P variant of the Pace in 1962-3. It is listed in the 1964 Pace spare parts manual, part of which is reproduced here:
http://www.vintagemowers.net/mower_pace.php

The engine looks very similar to a VK30 to me, but I'm not a Kirby Lauson guy. Perhaps the next step, if you want to acquire all the details, is to track down a copy of that spare parts manual.