Well, here's the unfortunate part about trying to match up the o-rings, they disintegrated when I pulled the line off.

You said you put the smaller o-ring in, then the plastic piece, and then the larger o-ring? The channel inside the quick connect is all the same size, so I am putting two o-rings in that are the same size, both of the 3/8" o-rings that are in that kit. One on each side of that hard plastic piece.