You’re on the right track. The part of me that goes to shit quickest is my feet from uneven terrain. You can’t duplicate that in a gym IMO. Hiking in real off trail conditions helps. Walking back and forth side hilling with a weighted pack and your mountain boots on a steep hill will help prep your feet and ankles.
Don't forget about the mental aspect of the hunt. I believe that a good attitude trumps being in good condition. I've seen guys in far superior shape that myself (not that hard to do) that really struggled on different hunts. There are times you are going to feel like complete crap. Don't forget to drink, eat and sleep. Sounds silly but you can go south fast when you are burning tons of calories and not replacing them. If you can manage a few trips with your pack and gear that would be great. Even if it was car camping and taking a good long hike during the day. Your ankles, feet, legs really need some time in the outdoors with a loaded pack. Maybe not 60#'s but a solid 40-45# will help you a ton when you hit the field.
Bring a bow or a gun. Not both.
Embrace the SUCK and Remember to have a good time and soak it all in.