Well, I am pleased to report that so far, pick up, put down is working really well. O is having his 3rd nap, in the cot. All naps today have been in the cot. We've had one waking before he was ready to get up. And he has been cool, calm and collected all day. 
He has done 9am get up, 10.15 feed, 10.30 nap in cot, waking at 1.10pm. Feed at 2pm, nap 3-4pm in cot. Feed at 6, then nap in cot from 6.30 til now. Bed time will be 8.30-9.
Each time we have done pick up put down, so he has self settled.
DP was doing different things previously, but he has now agreed to do what I am, so we have consistency.
Fingers crossed this continues I think we all know, it won't!!.
I should have maybe waited the clocks stopped fucking round!
He's got 2 clock changes in one week thanks to us going to Switzerland. I'm just going to keep him to BST when there, even though my dads wife will be utterly horrified at a child going to bed between 9-10pm. Tough shit!