(Looks like I posted at the same time you did Texas Q - late again as usual)
Hey redy2smoke also notice that the top portion of Texas Qs' smoker is rolled or tapered in, could this have been a solid construction barrel that has had the bottom cut off and inverted? I did notice the intake air holes located at the bottom like the standard BDS design.
Sorry I have been away from the forum for awhile and I may have missed any construction pics that you may have posted Texas Q, it is a good looking smoker and I bet what gets cooked on it really taste good too.
As for the extension on your offset I also positioned the exhaust on my offset/reverse flow smoker lower in order to maintain heat. You can tell from the photo that the stacks are not positioned on top of the cooking chamber but enter about mid point from the back side. There is adequate exhaust flow and I have not experienced any of the stale smoke taste with this smoker.
But for all out fun at home I use my UDS.