Hi yes he is now just 4.5 months however I think a max A time for him is 2 hrs. When I take him up for a nap and do his routine I tend to do that after 1.5-2 hr of A time when he starts fussing or I see him yawn and rubbing his eyes. I am sure that the screaming is because he is tired as it comes in waves and in the quieter moments in turns his head into my body and starts to drift off before then starting to cry again after a few seconds.
Anyway after reading your post and thinking about it I decided to go for it yesterday. So I did our usual short wind down of sleeping bag, book and cuddle, placed him in the cot with the white noise on and did a version of shh pat you mention below where I pat his thigh by his nappy and sing very softly. To my surprise it worked after 10 mins of crying. I did it again at bedtime, which took 40mins as I think he was OT but he kept turning his head to the side and drifting off before crying again so I knew he was close and carried on. Bedtime last night was 7pm which was amazing as it has never been before 8pm and I expected him to wake after 30mins but he slept until 11.30pm then woke for a feed.
I have just put him down using the same technique and again it took 10mins so I am pleased with the progress we have made, and plan to keep going now in the hope it gets to around 10mins each time and he needs me less to do the shh pat equivalent. However, I do feel really anxious each time ido it that it's going to go badly.
I am only doing this for daytime naps as at night time he suffers a lot from trapped wind and tummy pain so then when he wakes I give him a cuddle and rock, which soon sends him off. Until the tummy situation is settled I am going to continue at night this way as whilst he is unforcomfortable it doesn't seem right to do anything else, and perhaps if the daytime naps are sorted, once the tummy pains are gone the night times will improve naturally with less waking.
We go on holiday this weekend so I am hoping to have a fairly good routine sorted with him by then so he can have daytime naps in his cot while we are away free of any rocking by a tumble drier!!
Thanks again. Hope you think I am doing ok