Besides my project which is S/N 9, other PJC-2s that still exist include:

Matt Malkin's flying S/N 7, now based in Seattle.  Matt's plane has a Warner 165 engine.  Matt inherited his plane from his grandfather, who owned and flew it in Salinas, California for nearly 30 years.  Here's Old Mac in front of the plane in 2003:

Joe Harris' project S/N 2 is in Oklahoma.  Joe's airplane started out as a basket case that was abandoned in Florida.  Due to extreme corrosion, Joe has practically built from scratch the entire fuselage and wing, has built a new cowling, and repaired most of the control surfaces.  Joe and Ron Decker, who is working with Joe on the project, are on track to have a show-winner when the project is complete.

The EAA Museum's display airplane S/N 6, in Oshkosh.  This aircraft is very authentic, but it is not maintained in flying condition by the EAA.

This aircraft is serial number 1, located in Arizona, and used to belong to Mel Heflinger.  It has been written up in aviation magazines several times.  The paint scheme on this aircraft is unique in that the vertical stabilizer white section shows the outline of the original stabilizer and rudder.  The orange shows the enlarged stabilizer shape with which the PJC-2 was ultimately certified.

Photo linked from 1000aircraftphotos.com

The story behind the stabilizer enlargement is that during the CAA (precursor to the FAA) type certification test flights, the CAA flight test pilot put the aircraft into a spin from which he couldn't recover.  The pilot bailed out.  The plane went into a flat spin and pancaked into a field.  The CAA was embarrassed by this, but they forced the Harlow company to enlarge the stabilizer to aid in spin recovery.

Lastly, N54KC belongs to David Callender in Arvada, Colorado.  This plane has a 185 HP Warner engine.