Hi Tom--
Your dad's LC is in beautiful shape, and I'm sure he's smiling down from the stars to see that you're putting it to good use. You may well know this already, but LC's are prone to recoil-induced cracking behind the lock plates--a good double-gun 'smith can prevent this from happening by relieving a little wood in the critical place beneath the edge of the lock (and possibly replacing it with epoxy). If it's done right you can't see this fix from the exterior of the assembled gun. I can't tell from the photo but your LC is in such nice shape that I'm assuming it to be so far uncracked--but it likely won't stay that way if you continue to shoot it, and you absolutely should continue to shoot it. A minor preventative measure will keep it in top form for the future. Good luck, and congrats on your canvasback.
Malcolm