Hi All, I think Ed Solomon would be a better expert to ask about. I have had the pleasure to play numerous G basses and they are of very limited use in the US. I really, really want to use mine with smaller tenors for early Romantic works in some of my orchestras, however getting modern tenor players to use small horns can be tough.
The .487" bore of standard G basses is bright. OLDER G basses are often leadpipe less and while bright they are more open blowing that you would expect.
One fun thing is that the slides for Imperial (Modern
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Betty model) G-D basses are long enough for an F bass.
So, IMO you will have fun with a G bass. Will you get to play it in a modern group? Unlikely.
I had an opportunity to use my Imperial G-D bass for the lone bass trombone part for the Chopin 2nd piano concerto. The reason I didn't was because it has a hard time playing up to A=440hz and I didn't want to play out of tune. Many old G basses for the British market are old high pitch as well, which are A=452hz. One of my deceased clients had his Fathers 1920s Boosey orchestral pitch (440) small bore. IT had a medium shank leadpipe less setup with very lightweight construction (thim walled) compared to some of the thicker guage brass band models from later. That particular .487" instrument had a lovely sound (until FF).
The rarest G I have played was not my Imperial. But a Conn 88H! G BASS from the 20s. Before the model number was reused for the tenor we all know it was used for a large bore G bass. .547" slide with soldered on stockings, barely 7 position (7th was at the very end of the stockings), a small 7.5" bell, but indeed the rest of it did look like a stretched out 8H with a small.bell diameter. That horn had a nice round sound.
The most unusual G bass I have seen is owned by Noah Gladstone. An east German F bass that was factory cut down to G for the brass band market. It was not a fun playing experience. Small slide bore, huge throat, bad intonation, and an awful slide. The sound could be something however.
OK story time over....
Benn