The pgp-send body should just be:
set TO = $1
cat | pgp -fe $TO | /usr/ucb/mail -s "encrypted mail" $TO
Can always check:
ftp://furmint.nectar.cs.cmu.edu/security/pgp-send
ftp://furmint.nectar.cs.cmu.edu/security/pgp-receive
For latest version...
-- Vince