Mitch, the supplier of the wurst (German Deli, Borough Market, London) lists currywurst among its many tempting German scoffs. Fairly expensive and may be out of stock because of current situation.
One thing I just cannot find anywhere in the UK is the Dutch haring. Simple salted herrings sold everywhere on street stalls in the Netherlands. Unique, delicious flavour. Perhaps with new Van Der Valk coming to TV this week, we might see some soon?