Okay, the guy at e-RAM is having me send in the fan to see if there's something wrong with it. He assures me that the new plastic one is not weaker or cheaper than the old metal one -- he says it's more efficient, in fact.

The motor inside, I observed, is a model airplane motor made by Astro Flight, which from what I've been able to glean off the web is considered a high quality product. But I haven't been able to figure out which particular Astro Flight model it is. Might be a 608 or 610, or maybe a 305 or 306 intended for model boats instead of planes.