hasn't the 26" length always been the scarcest ~ least popular in doubleguns?
Dig or one of our other UK friends can probably provide better detail on this, but I think Churchill managed to sell a few XXV" back in the day.
Because I (attempt to) use the instinctive shooting style, I have always wanted to try a Churchill XXV with the special rib in the field, like Churchill advocated. Unfortunately, I have not met anyone yet who owns one - proving your point, perhaps. I think AyA still offers a "XXV" model - I wonder how many they make every year?