Wreno,
I try to keep links to all the active clubs at the other forum. If you see any missing let me know, and I will add them, or feel free to sign up, and add the links yourself. We have to temper the conversation at the Micro forum, because there are a lot of young people running cars. But the site owner has been very gracious with the bandwidth and storage space, so we have "kept on" there.
I suddenly remembered that we have another small type VII I believe. It has been tested, but not seen any actual combat. And you can view a typical air gun schematic here Cpt Nemo12
http://www.nwlink.com/~pfleming/Images/BasicGun.JPG
Here are a couple photos of the sub.
And i managed to find a small image of a torpedo test. Torpedos are just 2" long x 1/4" aluminum rods.