Bill -
Couple of suggestions.
If you are going to put a Checkcord on the dog, make up a real shortone( 1 meter or less) and clip it on the puppy when it is running about in the yard. that will get the dog used to running with something attached and dragging.
LCS might be willing to sell you just the cord so you can buy 50 ft and make up whatever length you desire.
Toss pigeons in the field.
A pro I know starts his setters off a 4 wheeler. He has a big bag of pigoens on the 4 wheeler and when he turns out the puppies, as they run about, he will toss apigeon and they will chase. He calls to them and when they come back in...he tosses another for them to chase. The puppies learn that he is where the fun is at and come in readily after a few sessions. They also learn that they cannot catch birds. No reason the same tactic should not work just dandy for a brittany.
Install a come command.
i do this with two checkcords, two persons and treats. I try to do this with a pup that has not eaten yet. Hungry puppy makes fotr willing trainee. I sit in the yard about 20 ft from the other personwith the bitter end of one of the checkcords in my hand. The other person sits with the bitter end of the other cord in theirs. The pup is in between. I call the pup to me. if it comes in...great. If not, I gently reel it in. In either case, I pet the puppy up and give it a treat. Then the other person gives the call command and repeats the process. In fairly short order the pup will be running back and forth to get the treats and it will become necessary to restrain the pup and release it when the other person gives the come in command.
Lastly...you can just turn and walk away. Pups do not like to be left out there and will hustle back to you(especially if they know you have a pigeon handy). Hiding behind a tree or tll bush does the same thing as lying down and does not require the services of a rigger and a hoist to get me off the ground.
I LOVE a bold, independent dog. Have fun!
RayG