That is interesting reading, Jeff. I wonder if the problems were resolved with the supplier by now.
I was looking at the Gardner system because the 304 SS one I had made back in 1987 (I forget who did that....some place in Ohio as I remember) still looks brand new but the bend into the tunnel on the right pipe isn't as opened and smooth as I would like it to be and seen with steel pipes.
During the cars re-restoration now I am looking at installing resonators which is why I was looking at Gardner but I just may look at the alternatives you posted too before making any decisions. I'm not going the 'judge on a lift' route so having an exact repro isn't as important to me.
Thanks for the info,