The first corner I printed is the top front left corner.
It printed pretty well.
So I decided to print the 3 other top corners.

Here's my result :

I've read somewhere on another blog that Chylld is a part design genius.
I completely agree : the design of these replacement corners is amazing !
Chylld has been designing them so that the overhangs are in the acceptable limits to be printed without support (except for the Y motor corner that needs a little help to print...).

I haven't tried to put them in place yet but they seem to fit well. 

That really is a great piece of work Chylld !