UPDATE for those who are interested.
Bought 16 day old ja757's from spilsby but the farmer gave me "two spares" as he put it, at the end of February. Started them off in a big old incubator and slowly dropped the temp to about 25C then moved them out into a small wooden hen house and run that i made which was heated with two 60 watt spotlights. they stayed inside for about 3 weeks altogether then started moving outside. At about 4 weeks i moved them to a hen house behind electric netting. The first two nights were fun :roll: trying to get them to go into the house. There was also the day i forgot to switch the fence on and they just walked through it and i found them all over the top of the garden. Fortunately the fence has trained the fox so well that from being a daily visitor he never even comes into the garden anymore. I had one fatality at about 7 days and another one at about 8 weeks but all the rest seem/seemed relatively healthy. I dispatched a pair at 10 weeks for the barbeque, then another four for the freezer and then yesterday one more for dinner today. Leaving nine still running around - actually that's not quite true - they are the laziest birds you could ever meet. They eat and sit down, drink and sit down, walk five paces and sit down sometimes they even shuffle about rather than stand :shock:
They eat and drink so much that they were getting through 3 gallons of water a day and a huge feeder of growers pellets and when i replaced it they would always do a fantastic impression of a rugby scrum.
Anyway they have plenty of meat and are very tender, but i must admit the plucking gets me down as it takes so long.