That's a pretty decent and clean hinge for it being leaning willow of that size! Nice work!
Going back to the topic of leaners and what cut/face to use, there's an alternative method using a standard Humboldt face or a pie-face. It's common-sense in my mind, but I've seen lots of people not apply it.
If you have a moderate leaner, instead of putting a face in like you would on a straight trunk, which would be perpendicular to the angle of the lean, keep the face parallel with the lean. Using a pie is safer if you don't need the butt to leave the stump, but can also increase the chance of chairs, wood pull, and/or uprooting, species-dependent.
I've used it on smaller ( >12-16") heavy leaners as well, but it's riskier, and, as always, KNOW YOUR SPECIES AND ITS TENDENCIES.