"I went to level **1-3** and got over 44 coins. I think I got about 65 coins."
There's your problem. The mushroom house is in 1-4!
And the others:
2-2: 30? coins
3-8: Erm.... 42 is it?
4-2: 22??
5-5: 28????????????????????
6-7: 78. The only other one I know for sure.
7-2: Bleh. Don't ask. My guess is 42.
Those values are from memory and are likely wrong.
P-Wings are found in the World 1, 3, 5, and 7 Mushroom house, and after the world 1, 3, 5, and 7 castles. I think, don't quote me there.
Congratulations! You have just been blessed by the wisdom of Steve.