Hi there Icrcreamslick! What a clever find about the TBU system! Thanks for sharing it with us. I'm sure it'll come in very handy when your Sherman is cornered by a couple of Tigers. I think I'll go with an internally mounted LED. I'll miss having the LED on the barrel because mounting the LED internally eliminates the variable of cannon elevation. With the LED on the barrel, and on hilly terrain, its great to control the angle of the barrel to make a hit. It just makes for a more realistic gaming situation. Thanks again!