I think a score of 6/6 for a Lab is fine. Why don't you register? There are plenty of Labrador owners on this board (I'm not one!) who will be very helpful to you.
Hi 6:6 is very good but you must get his eyes tested too. There are many Lab stud dogs out there and many of them are champions of fabulous breeding, so you will have many dogs to compete with for stud work, so be sure that you can warrent using him as once will not suffice. P.s I am a Lab person, :) What lines is he from?