How does this look Damien?
I followed some of your steps and tried a few different things as well.
1st I took a larger brush and liquified the eyelash line on the eye on the right down. I had my finger on the screen to see how far it needed to go to match. After, I masked the original eye back up to meet the new line. I hardly moved the natural eye crease, so I didn't put it back.
2nd I selected the eye on the right, flipped it horizontally, and used the lashes from it to mask in where the other eye's lashes had flipped.