Yes, we don’t seem to be getting anywhere and I can only reiterate that certificates might be more helpful.
In 1881 5171/11/3
William Clarke has been transcribed as William B but if you look at the census page, it looks like ‘N’. In fact there have been user submissions with corrections to ‘N’ too.
In 1891 4300/115
William Clark has his birthplace as Hensingham. This seems to be in Whitehaven district.
There is a birth December quarter 1861 Whitehaven
William Nevason Clark with no mother’s name.