You might think it's bad these tubes are un mounted, but the are all for sale and can be put back to work.
Click on this link
Action-Report-4th-Mid-Atlantic-Shoot--IMA-Field-Trip and you wll be take to the post over on British Militaria where there a bunch more of these guns.
The rusty old wall gun with a tiller is shown being discovered in the History Channel documentary Treasure is Where You Find it.
If anyone can identify these please do.