OK Mick, you haven't had a reply from the experts so I'll tell you what I do and then, no doubt, they will all slate me if I've got it wrong! ;D
Close all the nest boxes up. Put in a 2 1/2 litre old paint tin in each. Put cocks in then introduce hens one at a time. Watch each pair as you put them together, she should nod her head at him.....if he's a bit aggressive, lift her onto the paint tin if she hasn't already jumped up there. Hold her on it for a minute then gently remove your hand and she should stay on it. I leave the tims in for a day or two till I'm sure they are well paired.
Open one box at a time letting the hen and cock out to eat and drink - do this for two days.
Open two boxes at a time one top row one bottom - or one one side one the other so they are well away from each other. Do this till they can find their own boxes easily.
Over the next few days keep opening more boxes till you can leave them all open and they can all find their box.
Put the nest bowl in.
Wait for the eggs!!