Wervershoof? Never heard of it? Perhaps if you are a fan of older Moto Guzzis. Because that is the brand that specializes in Nesville.
However, we found something that 'goes beyond the brands': Enamelled mufflers.
In a time when chrome plating is almost unaffordable, enamel coating may be an option. Certainly because we are in a time where black enamelled exhaust silencers can simply be classic.
We already knew the phenomenon when it comes to exhaust manifolds from cars.
So maybe 'enamelling exhausts' is a Google search term that will help you further.