ithinknot recommended not replacing the leadpipe, but instead replacing the crook with something more properly sized for the .508 bore size. I used the MK Drawing Olds Recording crook in nickel.
There's a nice bonus that the crook is a bit wider than the stock Bach, so the slide is ever-so-slightly wider, not something I would complain about ever.
First impressions are VERY good. It retains the sound and character that I associate with this horn- a really beautiful color and zing, but now partials seem to line up and respond in a way that I expect. Before, I couldn't play the horn with my Doug Elliot D3 shank- it would just go full woof-zone and not center anything. Now it feels like a .508, and I can really pump out some noise on it.
Excited to try it in some real world situations... someday!
![Image](https://i.imgur.com/YvoCKxK.jpg)
![Image](https://i.imgur.com/3ikKTjF.jpg)