When you pick up 45HP from fixing the ports and cam

What's all that black stuff on the second pic in the chamber? What colour was the exhaust valve in the that pic when you pulled it out was it black or a tan colour?

I personally wouldn't place any emphasis on a dykem test because it doesn't take into consideration what all the fuel that's on the walls is doing. Simply spraying some colour in the centre of the port would not even remotely replicate what happens in the running engine in my view.