Smithfield Country Ham -- cut in half before cooking. Mistake?

It shouldn't...   Simmer, I think, means submerge in a liquid at about 170-180 degrees to thoroughly cook...  You do not want to boil the meat..   Check the internal temp, of the meat, and cook until it reachen the temp the manufacturer suggests...  Probably, a guess, 160 ish...   

To boil salt cured ham, the Smithfield Marketplace recommends placing the whole ham skin side down in a pot and covering it with cool water. Bring the water to a simmer, approximately 190 degrees Fahrenheit, and let it cook for 25 minutes per pound of ham or until the internal temperature reaches 163 degrees Fahrenheit, adding water as necessary to keep the ham covered.

To bake salt cured ham, Appalachian Traveller calls for placing it with some water in the oven at 250 degrees Fahrenheit for 25 minutes per pound or until the internal temperature reaches 163 degrees Fahrenheit. The ham is finished when a knife encounters little resistance when pushed into the meat, which pulls away from the bone easily. Skin the ham, removing excess fat, and broil it with cloves and a brown sugar rub, vinegar and dried mustard until the sugar melts.

Preparing salt cured ham involves cleaning it, removing excess salt and mold, cutting off the hock, and soaking the ham in water. Food Network's Alton Brown recommends a two-day soak, changing the water and turning the ham twice daily.