Awesome, thanks for finding the build thread.
I bet the handle is a run of the mill injection molded handle around a threaded insert.
My initial plan had been to have 3 attachment points for the dowel on each wall, two at the foot of the bed, one at the full width of the bed, so the one rod could be moved back to a stowed position, but a sliding mechanism is much cooler.
My wife's insistent that an infant can't sleep in a canvas bed, so a temporary solid surface like Zach's may be required for a few seasons.