Combine all the marinade ingredients except the gin. Bring to a boil and simmer about 5 minutes, remove from the heat, add gin and cool. Place roast in marinade to cover. Let stand refrigerated for 48 hours or more. Remove from the marinade; place on a roasting rack in a large roasting pan and drape with bacon. Roast uncovered in a preheated 180ºC . oven for 15 min per pound. Remove the bacon for the last 30 minutes of cooking and baste roast with the strained marinade and pan drippings. Remove the roast and let sit 5-10 min before carving. With a little butter and flour make a gravy from the pan drippings and balance of the marinade. The gin is juniper flavored alcohol and juniper is a traditional game flavoring. The gin works quite well if you don't have any whole juniper berries available.