He drops the boots more often than the bracer, but even those he drops rarely. And he spawns at any of the ogre spawn spots except Oowomp, approx. once every game day(90 min).
One problem I've seen, myself and a friend both got a pair of the boots, and a few days after we got them, they disappeared. Happened after we had each died(at different times, happened to me first) and when we looted our corpses, they were gone. Petitioning got no response, so must be a bug involving them. Haven't heard about the bracer doing that, but don't know anyone that's gotten one of them.