changing csh scripts

[utzoo!decvax!duke!unc!lab]

Is there a shell script which will find old csh scripts starting with #
( and nothing else ) on the first line and change them to #! /bin/csh ?
This should find and change all such files ( and no others ) in a
person's home directory and recursively to all subdirectories. In particular
it should not change C programs, object/compacted files , etc.
I tried things with find, etc. but was not successful. A fix of this
type should be useful to many of us anyhow, so if someone knows how to do
this please speak up.