If you look online, then you could be forgiven for thinking that modellers are only interested in the foreign built stuff, but it really isn't the case when you visit shows, and actually take a close look at what submarine modellers build in this country.
I have seen lots of models of Hollands, X-craft (kits available of three different versions), chariots, E-class, 0-class, U-class, S-class, T-class, Vanguard, Trafalgar(at least three kits of those), c-class, and some scratchbuilt models of earlier craft like K-class, R-class even a Welman midget sub.
K-class and M-class are very specialised. Kit manufacturers want a product which will shift a reasonable volume, I don't think either of those would do so. The fullsize craft hardly distinguished themselves did they? Wound up killing more of our own sailors than any enemy.
Another problem with a lot of British craft, especially earlier pre WWII craft, is the difficulty of obtaining plans, photographs and other information. In contrast a lot of Foreign boats are extremely well documented.
I also think it's fair to say, that by the end of WWII the Germans were a long way ahead of us when it came to submarine design, and we, alongside the U.S and the Russians borrowed this technology heavily after the war, especially the developments in hydrodynamics.