Do I stick with the K81's? the classic look is great; they work OK (haven't fallen off). The front is a bit wider than the standard 3.25.
I would, yup. I agree they look right and they behave pretty well.
But their life is quite short these days - on the rear of 650s I get between 2 and 3 K miles (tops) from TT100s made here in France, pretty much regardless of how they are ridden it seems. Despite absolutely hating tyre fitting, I still like them.
One bike, a 500 twin, has a more modern-looking Avon Roadrider on - lasting noticeably better than the Dunlops at 4K miles and counting on a bit more, but lifespan could just be because it's a sub-30 bhp beast.
Not sure if there are any better choices frankly in 19", apart from things you wouldn't want on an RGS, like Mitas, or the old SMs.