Definitely let him off lead from day one. This is your very best chance to establish a good recall as part of his routine (it will go out of the window when he becomes adolescent and discovers his nose, but that's another story).
At the moment Griffin will be keen to be with you, so take some extra tasty treats like little pieces of cheese or cooked chicken and every time you see him starting to come towards you say "Griffin come," or whatever you choose, and reward and praise him when he gets back to you.
If 2 of you are walking him you can play a little game of one person holding him, the other one going a short distance away, then the first person letting Griffin go at a moment when he's focussed on the second person who can then call him in and praise and reward.
Can't give you any advice about lead walking though as I've clearly failed on that front. My 2 don't go on lead very much and think they're Huskies pulling a sled when they're on their leads
