Did one of those recently, same recipe. I use a Cambro food container with lid, clear plastic, kind of like a 6-gallon square bucket. Anyway, my advice to you is to take their number of days brining as a minimum. It takes a long time for the brine to penetrate a whole ham. Leave it in a few more days, maybe a week.
When I smoked mine, I smoked at my usual 225F to about 155 and ya know, that wasn't enough either. I broke mine down into parts and re-smoked them to 160 and after that second cook, put the bigger sections on my Globe slicer set to real thin and shaved the ham out. Now *that* way tasted KILLER!
just my two cents worth .. seattlepitboss