Nothing at all to do with the bike apart from the shell width (68 or 73mm), all depends on the chainset. Try the Sheldon Brown BB database.
My guess is 113mm.
As it's so easy for me to get there, I've visited most of the coastal stuff over the years - originally about 15 years ago with sons on the tandem, some photos back on pages 28 + 29 of this thread!
I am not sure that's right, seeming as SRAM changed their shift ratios between 9S and 10S. However one man's 'compatible works perfectly' is another's poor match.
Just back from a loop to see the Tour de France in Rouen. I'll keep it brief and let the photos speak for themselves.
Day 1: home to Poole (20 miles) for the 0830 ferry to Cherbourg, then onward 45 miles to Ste Mere Eglise (with the famous parachutist on the church tower).
Day 2: The excellent...
If you are running bar-end shifters then full size V's and Tektro V levers is a good way to go.
There is a hidden nightmare in all this with Shimano's change in road lever cable pull in recent years to NSSLR, this may be why you don't get much from the Dia-Compes. Have you tried the Tektro...