33a is a bird of prey.
I don't understand the preamble. I reckon the 6 unclued entries form a complete set, so I don't see how there is the remaining pair?
I see what the 3,7 is from sunray's posting but I don't understand the bit about having letters from the second word. Some or all of them? And I don't see two missing! The letters from the second word for me would be N, A and E. Four letters left over?
Is there an anagram of the second word in the grid?