I tried the Monette leadpipe again. It is about one receiver longer than the Bach, and it fixes the g nicely. Time to cultivate a local American tech to put it on. It will change brace placement for sure. (I had the braces removed Spada does [without the fine tuning] previously.)
As for slide shape, I don't like the edge that comes with the Bach D core. It just sits there and buzzes and there isn't too much ability to color it. Haven't experienced ovate slides on my D yet, but I find my round one gives me a warm, highly compact C sound that I like, kind of like a mythical Gil Johnson D sound. Thinking of moving the bell brace up a bit for more feedback.
Isn't playing with horns fun?
(That's another way of saying "Why didn't it work right out of the factory?")
Playing horns is even more fun, so please excuse me while I practice.