sed translate link arguments to make dependency

The following test script shows what I'm attempting to do. It will end
up in a make file translating a make macro for library list into a
macro for target dependency.

pre_fix=lib
suffix=.so
echo Starting with:
echo -L/usr/local/lib -ltom -ldick -lharry -L/usr/lib -ljane -ldoe
echo -L/usr/local/lib -ltom -ldick -lharry -L/usr/lib -ljane -ldoe |
sed -r \
-e 's|(-l)([^ ]+)|'$pre_fix'\2'$suffix'|g' \
-e ':a;s|(([ ]*-L)([^ ]+))+([ ]+)+('$pre_fix'[^ ]+)+|\1 \3/\5|g;ta'

# Use lines below if not GNU sed and -r option
#-e 's|\(-l\)\([^ ]\+\)|'$pre_fix'\2'$suffix'|g' \
#-e 's|\(\([ ]*-L\)\([^ ]\+\)\)\+\([ ]\+\)\+\('$pre_fix'[^ ]\+\)\+|
\3/\5|g'

Current output is:
sh junk.txt
Starting with:
-L/usr/local/lib -ltom -ldick -lharry -L/usr/lib -ljane -ldoe
-L/usr/local/lib /usr/local/lib/libtom.so libdick.so libharry.so -L/
usr/lib /usr/lib/libjane.so libdoe.so

should look like this when done:
/usr/local/lib/libtom.so /usr/local/lib/libdick.so /usr/local/lib/
libharry.so /usr/lib/libjane.so /usr/lib/libdoe.so