blaineak wrote "I believe the head issue is because you need to create a new character file with the new head."

Your suggestion to add the P4 runtime to P5 is very good and should solve most of tropob's problems, but I don't think it's necessary to save a custom-headed character to the library. When trying to reproduce tropob's problem I was able to import a customized figure from a saved PZ3 scene file without saving it to any runtime library.