Okay so i started the process and moved my stand into the house, and of course its not level.lol, Secondly I don't have solid flat/closed surface, the tube stand is open on the bottom. I bought some of the wood plastic composite shims from home depot to see if that will work, but my main concern is the bottom not being flat. I have a pictures attached. Any ideas to make this level and safe or do you think the composite shims will be fine.