I really love my Bach LB american model cornet for jazz stuff. I also just bought an 1886 Conn Wonder cornet (can't wait to get that!) but I prefer the American cornet for jazz over the Shephard's crooked models. Maybe my Conn (which is crooked :) will change my mind.
Here's a clip of me playing the Bach... it's certianly not Ruby style but I enjoy getting "around" on the horn.
Softly on Wedge 3A - Putfile.com