Would of is wrong wrong wrong. But many people use it so it is right right right.
Would have is right and so is would of. Would of is correct by common usage.
So many editors and writers forget that language is a living thing. Whatever way people use language is ultimately correct. If we all started saying “me hungry” rather than “I’m hungry” then me hungry would be correct.
I remember many arguments … err … passionate discussions with other editors regarding commas. I’m in the commas are upturned chairs on the path to comprehension group and so I edit accordingly.
I found, to my surprise, that he had turned blue.
I found to my surprise that he had turned blue.
Oh no! Suddenly people can’t understand it! Pfft.
I found to my surprise he’d turned blue.
To my surprise he’d turned blue.
Anyways, the point is that grammar is very useful and we should follow some rules but not at the expense of the living language.