Well, you’ve rattled my cage.
Look at the bottom two pipes in the picture. They’re in a design that I created myself in 1997, laboring for hours to fulfill the idea of a Prince mated to a Canadian shank: I call it a Canadian Prince.
The hard part was what to do with the traditional prince shank and stem, which often have a gentle curve. Ultimately what I figured was to use a slightly more angular bowl shape. That made an oval, straight stem shape work better.
I must have looked at hundreds of executions of the Prince shape on eBay and the web in general. Finally, a friend who maintained a website that sold pipes shared a picture of a Prince by Ashton that nailed the bowl shape I wanted. He told me it was based on an early Dunhill Prince. Unfortunately he wouldn’t part with his Ashton, but he sent more pictures and took some measurements.
My first commission was the natural finished one made in 1998 by Paul Bonaquisti in his “Ruvido” rusticated finish.
The second commission is the black stained pipe made in 2015 of so by Bill Boyle.
(The other four Prince shapes in the picture are, top to bottom: ‘69 Dunhill Bruyere with shank repair, Christopher Askwith, Ben Wade, and Peterson.)
I suggest looking at every Prince shape you can find and — once you see one that rings the bell — ask a reputable carver to re-interpret the shape for you. Don’t demand a duplicate, just find some inspiration for a talented carver.
FWIW. It’s getting late, but I can share better pictures tomorrow if you’d like.