For old venison (old bucks) which some parts of can be quite gamey, I have used a concoction of water, wrochestershire, oil, vinegar, bay leaves, thyme, with garlic and onion powder added, and the key item, about 10 or 12 crushed juniper berries. Bring everything to a boil (except oil) for a few minutes. Remove from the fire, then add the oil. When completely cool marinate for 4-6-8 hours or so. This will "disguise" the flavor of the gamey flavor somewhat, but will do very little to tenderize the meat.
I like the bourbon idea too! Pour two ounces in a glass, and slowly sip while the meat is cooking!
Relax, Have Fun & Enjoy!