Thank you to everyone for your advise. I know now, that I'm not alone with my little problems and I'm grateful for your help.
I just could not find time to reply earlier - Luke (now almost 8 month) is still a very early bird. He wakes now up between 3 and 4 am. We tried to give him tea, but I could not bear the tears and crying anymore. So, he still gets his early bottle. He will go back to sleep often for another 45 min or 1 hour, but before 6.00 am he is awake again, often just after 5.00am.
I try very hard to increase A-time, but have no luck. After 1,5 hours awake he starts yawning and kicks his toys away. Even reading a book to him is difficult. He does not want to sit on his own by then, so I pick him up, go for walks in the garden or "talk" to the dogs. After 2,5 hours time is up and I lay him down.
But there is also some good news. I bought new dummies again, as things escalated in his cot. It was just not to bear anymore - for both of us. I also went to our paediatrician, as I wondered, if he had an earinfection (he had fluids in his middle ear before) or something else. But luckily he was fine - a big healthy boy. I asked the doctor for advice on the sleep issue. His reply was, that the only proven method to "sort him out" is to let him scream.... He said to me, in case he vomits, I must then take him out, clean him up and then put him back in his cot. I could not find words to reply and left....
In my heart I knew I can do better than that and I also knew, I had to change this situation. Well, what really helped is, that I use now a VERY strict voice. When it's bedtime I cuddle him and kiss him before I lay him down and than I tell him with a deep and strict voice it's time to sleep. It took a few days, but now there is no more screeming, he is just VERY noisy, but this is o.k. for me. He will still take his cot apart and fight his sleep - a blanket I can only put on him, once he is asleep, otherwise the feathers will fly around .... His poor teddy bear has to take all the punches. It's like a miracle to me! The only habit I can not understand is, that he will trow his head from one side to the other x-times like madness. Quite scary.
What is actually a "Mantra" cry and a temperament test?
Thanks again.