This must be the other Richard you mention:-
baptised Lewknor June 23 1805 Richard Neighbour baseborn s/o Sophia.
I didn't find a burial for William (1820) nor did I find a marriage for him, but he'd likely have married after 1837 and that's where these marriage records stop.
I did find these marriages which might be of interest -
Apr 24 1810 James Hawkins of Wheatfield & Sophia Neighbour
Witnesses: Thomas Neighbour, Susan Auger, Charlot Hayes.
May 26 1836 Robert Neighbour b otp & Mary Ann Waklen sp
Witnesses: Richard Neighbour, Elizabeth Walkelin.
Sophia was the sister of Thomas:
Thomas Neighbour May 4 1783 s/o Richard & Elizabeth
Sophy Neighbour Jun 4 1786 d/o Richard & Elizabeth.
Another Richard for you to cope with!!

Jill