I build my own tank stands out of pine / 2x4's and 2x6's - I recently built two for my twin 75's. I finished both of them, before putting the tanks on, since they were painted and all. One is perfect, but the other one has one corner that is 1/16 off, so the tank on that corner is almost 1/16 "off" the top. It rocks, as a result. How can I remedy this? I'm not going to be able to just raise that corner of the top. What can I put under the tank on that corner, and still keep the integrity of the tank?