OK, so I'm totally guessing. I have a 9 week old and I'd leave him to sleep. maybe only 45 mins though and then watch for sleep cues on the next cycle, which may not be very long at all. I'm guessing if he's taking 1 hrs to go down then either he wasn't tired enough, or he was too tired. Some times by ds has 1 1/2 hrs awake and sometimes he had only 45 mins. I generally put him down when he gets fussy and nothing will help (change of scene, or different hold). If he is overtired i have resorted to a quite breastfeed to relax him, but I try to make sure he doesn't fall asleap at the breast (which he usually doesn't as he needs to burp).
Not sure if any of this is helpful and I'm hoping that someone with more experiance will jump in