I agree with the others on the floor lamp for threading. I've run into a few rifle floor lamps lately. You can get one of the lamp pipes that are standard 1/8-IP threaded for less than a buck at the Home Depot, might be worth picking one up or taking apart one of your wife's lamps to test the theory.

Was there a buttplate? are there screw holes in it or in the wood under the plate. They would have had to secure it somehow