All I have is this........
the tower was made from two blocks of plastic card, the upper section having been cut to accomodate the cannons.
References show that the barrells rotated up and down so I used two coffee jar lids for the "gun wheels" with ends of plastic garden ties to act as the "cogs".
The gun barrels were built from the following......
1. Lifecolour paint jar.
2. Screwdriver handel.
3. Spare afterbuner cans from other model kits.(3 differnt scales/types glued together.)
4. The shaft from an old scribing tool.
This was all done on the spur of the moment with whatever I found in my spares box and withing my workshop that evening. It really is surprising what you can do with a few spares.