I think a nice wood baffle instead of the light lens and a good paint job, these would look wicked sitting on top of a short pole. 8" woof and a tweet maybe.
I'm going to grab a pair. the only problem I see is figuring out the volume. My thought is to seal them up and fill them with water then measure the water then convert it to cu ft.
They are very thick walls. They had to hold up to weather all across the country. I would still stick Dynamat on the inside walls. That is what the car audio guys use in cars to stop the ringing.