Not sure that that is the same. The Camp-Inn looks like it is one solid stick that the lower end rides in a track; open the hatch and the bottom end follows the track until the hatch is all the way up. Gravity keeps the prop at the bottom of the groove, and the angle of incident is what keeps the prop from lifting up in the slot with wind loading. Lift the hatch a tad, push up on the prop to get it started back up in the track and the action of the hatch closing forces the bottom of the prop up into the guide slot.
At least that's what I think I'm seeing.
The one Norm linked to is a multiple piece extending prop rod that telescopes into a locked position with fixed ends.
That Camp-Inn set up is pretty slick, elegant even. With some careful sketching, perhaps a scale model (or two) of the geometry, you could get it close enough to bring it to full scale for some final fine tuning and make that work. Might want to use a good strong piece of select wood for the prop, and probably steam bend it to get the right shape w/o creating weak spots. It will be under a considerable load with leverage and that kink shape to it.
I like it.
