DJ Hekla released a few remixes and 7" single on Planet Mu. He also wrote liner notes for Hrvatski' debut album Oiseaux 96-98, produced dj-mix together with Keith Whitman and supposedly was responsible for artworks and packaging design of RKK releases.

Later Pieter Christophssen (Mr. P.C. C.P.) name was associated with Reckankreuzungsklankewerkzeuge imprint. Commenting rumors of his involvement with the label, Whitman first said that Mr. P.C. C.P. was a joint pseudonym for a group of record collectors, early electronic music enthusiasts, sound engineers, etc. but finally admitted that he is Pieter.