No firebox leaks and it throws off a LOT of heat with just a few small hickory branches. Thermostat control for the damper worked well, too.
Rather than spending $127.50 for the motor and blower then fabricating a mount out of sheet-metal, I'm thinking about just putting a couple of box fans behind it. It really looks like a dedicated blower does nothing more than blow a little bit of air across the firebox anyway. There are just way too many places for the air to escape without hitting the firebox.
Whaddya think? And if I find that it's still not removing enough heat from the firebox (watching the damper action should give me a clue on that), then I could go with the dedicated blower setup and try my best to use sheetmetal to force as much air as possible over the top of the box.