Thank you for all your replies.
The censuses and marriage are definitely correct. The baptism of Henry also seems to relate to a brother, but what does the Hy in the address "Terrace Hy" stand for?
Leonard is definitely not Philip West's father, but his brother Philip might be. However, that Philip was probably born or baptised in Sussex in Oct 1786, not in St Nicholas Acons in the City of London as stated in the marriage. Is there any baptism of a Philip Elen in London around 1786 to 1792, which would rule the Sussex Philip out?
Also, is there a death between 1841 and 1851 for the father Philip in Middlesex and for the mother Elizabeth West Elen about 1857, probably in Islington?
Many thanks for all your help