Do you have your size in other shoes/lasts that we can compare to? Alden lasts? Other C&J lasts?
For what it is worth, I have a Skye 2 in 335 last and I find the same size in a 341 last is a little longer and a tad more narrow, but I can wear the same size in both. In comparison to US sizing, I wear a US 13 in barrie and trubalance lasts, which some people say run a 1/2 to a full size large and I wear a 13 in 335 and 341 last. The 13 in the 341 last is a tad bit longer than I would like, but fits okay.
I tend to shy away from using such comparisons as it seems I don't follow the usual trends. I have flat-ish feet with a narrow heel and wide forefoot, as well as a slightly longer left foot -- thus my troubles. But here are the sizings that I own:
Alden Plaza: 8.5 D US (a bit long, but width is perfect)
G&G TG73 and deco: 8 D UK
EG 82: 8 E UK
Carmina Soller: 7.5 E UK (purposefully a tiny bit loose to wear with thick socks - 7 would be a tight fit)
C&J/PRL Lindrick 7.5 D US (a bit cramped in the toe area for my left foot, size 8 would be better in length, but I fear would also be too wide)
C&J 341: 8 D US