I'm comparing everything to the Curran on the right stand-

I have three Bach 50 bells- 1981, corp, and corp screwbell. I also have three slides at the moment, Edwards DBN (dual bore, nickel crook), Shires B62/78 (dual bore, nickel crook), and a stock '81 Bach 50 slide that was rebuilt for me. All is played on my Olsen axial setup, seamed copper reverse Hoelle tuning slide.
'81 bell pairs well with my 50 slide (the slide it came with, actually) and to a lesser extent my Edwards DBN. With the Shires slide it gets a little thinner, nasal perhaps. It's still a good sound but just not it. I was playing this recently against the Curran and really wondering if I should keep the monster at all. Turns out it was just a bad match.
Corp bell matches perfectly with the Shires slide. It's by far the closest sound and playability to the Curran model, though with more color and I think a bit less dynamic headroom before the color takes over. I'd need to play them more though. It also works with the other slides, though the Edwards makes it a bit tubby, something less refined.
Screwbell does NOT work with the shires, it's more of the same with the '81 bell- thinner, nasal, the broadness is lost. I've noted this in the past so it's no big surprise. DBN is ok with it, probably the easiest to play. 50 slide works surprisingly well too.
What did we learn? Setups can be ultra picky. You cannot just throw components together and get a good instrument, even if everything is good by itself. The Curran is a great example, you can piece together a random Shires with all good parts that SUCKS. And i can do the same thing with my monster bass. Finding a combo that actually works is really worth the time and effort