building rosbuild-package upon catkin: making .pc wrappers?

Hi list,
I use orocos (2.7) with ros-hydro, and want to port some robotic software to this
(We have a Philips Experimental Robot Arm, of PERA, and want to port the available
software from Eindhovens Amiga robot to our setting.
We are mainly interested in control stuff, hence the interest in orocos)
In the end I want to migrate all components to a catkin based version, but for the moment
I keep the software as is in a rosbuild environment in a separate workspace as described in

This seems to work ok, but some *.pc files are missing: rtt.pc, ocl.pc and orogen.pc
Why is this, and why is this a problem?

There is some mentioning of wrappers and I made some fake *.pc files for them.
This seems to work fine, but the question is, is this the proper way?

Thanks in advance,