Magic, thank you. Upgraded to PBP3 and it all works on 18F27J53.
CCP1/2 had to go to CCP4/5/6, and now we have three PWMs over USB (which was the object of using this device).

As getting USB working on 18F27J53 involves collecting various files and then some tweaking I'll convert the USB demo for this PIC and put them in one place.
(One day soon... )

Thanks again for all your help.