Can't comment on widths etc, but fwiw here is my experience
I ride a B-17 in a very upright position on my commuter/utility bike..... it is simply fantastic
I tried a B-17 Narrow imperial on my road bike. (miyata 1400 bars just a little lower than seat) this did not work.
I looked at the B-17 narrow compared to my sella italia turbo and the top shape of the b17 n was way less rounded.
I got a swift and put it on my road bike......it is great. Chose the swift because it looked closer in top shape to the the turbo than the pro or the swallow
I kinda eyeballed/measured the indents in the b17 and they looked like they would work with the swift width...the did
so for me top shape is more important than width
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Life is too short not to ride the best bike you have, as much as you can
(looking for Torpado Super light frame/fork or for Raleigh International frame fork 58cm)