I just bought a Miller keg at a scrap metal yard. After I left, I noticed a small hole in the bottom, maybe a 1/4 inch in diameter. It looks factory drilled. I'm at work so I can't test it, cut off the top, etc. Does any one have one of these that can confirm this is ok and this is an "outer" layer? or did I buy an unusable keg that won't hold liquid?