First thing I see is that it's short! How long is it?
As for getting 45 at 27 - you should be ok just but have you pulled it to 45# yet? If not that should be your next goal as you have very little wood to play with. The tiller looks good. Did you heat bend that deflex into the stave?
Also I'd be very careful about using your tillering board any further with this bow.
It seems to me that you are pulling the string in the center this will make your lower limb look stronger than it actual is when it comes to pulling it by hand. Your fingers will be a good way above center once an arrow is nocked and you draw this alters the leverage being applied to the lower limb compared to the forces your tillering board is putting on it. You can put a 'runner' out to the side to alter the direction you pull the string from.
So simple answer is pull it by hand from now on