It only took a week! How impressed am I with our super boys?
Basically all I did was stick to our original bedtime routine, but putting Tom in his new bed. That way there was only the one change for him to deal with. Then just putting him back to bed, silently, each time he got up. That took 3 nights. Not bad.
Next I started to put both boys to bed at the same time, but with the same routine, and I introduced Tom to the bedtime story - which Jack has had since he moved into that room. That went well too. Tom got a little giddy but I ignored the silliness and put him back to bed. By night 5 he was used to it.
Night 6 was easy and by night 7 we'd done 3 nights in a row without Tom getting up or crying!
Sadly both kids (and me) have now come down with nasty colds complete with coughs and wallpaper paste snot, so we are having disturbed nights while they are ill but even now they aren't giving us any problems going to bed and they do stay put... They cry coz they have headaches/woke up coughing/can't breath well, but we go in to them and for the most part they settle back down.