First of all: thanks for your work on Poppy and the models!
But regarding the Gazebo model I have a question: Will there also be a .sdf file? I have Gazebo 3.0 installed (without ROS) and there the models seem to be required to reside within the ~/.gazebo/models folder and follow the convention to have a model.config and model.sdf file.
I also tried to convert the URDF with gzsdf print poppy_beta_drf.URDF but unfortunately this was not successful:
Error [parser_urdf.cc:2635] Unable to call parseURDF on robot model
Error [parser.cc:278] parse as old deprecated model file failed.
Error: SDF parsing the xml failed