Had to get my couple of cents' in on this one: i really don't know why
anyone would ever complain about the way 'percs look: they are a natural
part of the shell, and having them present (they don't nessessarily have
to be mounted, since often the interior of  a shell is quite lovely....)
simply adds to the completeness and scientific value of a specimen.  As
to aesthetics, admittedly they don't add much sometimes, but is this
really any reason to disparage them??  As long as they are from the same
species as the shell they inhabit, they are a useful and interesting
part of "the shell world", and every effort "should" be made to obtain
and retain them.

-Ross.