From Sussex Marriage Index if you do not already have it
Salehurst, East Sussex, 6 Nov 1827:
Richard BOXSELL
Philadelphia WESTON, (B)
Witness wit:Thos.MANTLE.
Salehurst, East Sussex, 26 Dec 1801:
Benjamin BOXALL
Charlotte DUNK, (B)
Witness wit:Jn.WESTOVER;Jn.HEATHFIELD.
1841 Richard and Philadelphia BOXSELL and family were possibly in Greenwich, Kent. Can post this if you do not have it. Children Mary 10, Charles 7, Thomas 6, Ellen 2 and Charlotte 4mths. Ages and names fit. None of them born in county. Richard a sadler
From IGI
Richard BOXHILL bapt 24 Mar 1803 Salehurst
Benjamin BOXELL bapt 9 jun 1805 Salehurst
Charles BOXHILL bapt 25 Oct 1807 Salehurst
Parents Benjamin and Charlotte
IGI has some birth and baptism details for Richard and Philadelphia's children in both Sussex and Kent. If you do a parent search with their names you will pick them up, Mary Jane, Henry, Charles, Thomas and Emily in Sussex, and Charles and Thomas again in Kent
There are also some children baptised to a Benjamin and Charlotte in Kent as well, same church as Richard and Philadelphia's, Sandwich by Cranbrook, which is about 5 miles from Salehurst, but in Kent. Suspect it is the same Benjamin and Charlotte.
Ian C