On Wed, 11 Apr 2012 16:32:32 +1200, "Kathryn and Kelvin"

There is no guarantee that the place of burial (or cremation) will be
anywhere near the place of death. In practice it only has a good
chance of being local if someone had lived all their life in the same
locality and that theory can often be spoiled when people are buried
elsewhere with their parents (or with their spouse who was buried with
parents). Someone else has mentioned looking at the will (but an
executor is not necessarily obliged or able to carry out
burial/cremation instructions); the more usual/popular place to find
the location will be in newspaper death notices.
In this case you seem to be in luck as the Times has a death notice
for Richard which confirms Putney Vale Cemetery as the place to which
the funeral took place so there ought to be a burial record for him at
least. Unfortunately there is no similar notice for Maria so you'll
need to get confirmation of whether or not she is in the same cemetery
(and/or someone checking more local newspapers); note that she could
be in a non-adjacent lair if e.g. her husband occupied the last space
available and that her burial record might have no cross-reference to
her husband's if they were buried separately even in the same
cemetery.