If it's a picnic, then it's just the shank portion of the shoulder, or adjacent to the butt, so you're typically looking at pulled pork.
If the package says it's cured, though, it sounds more like a ham cut....like maybe the picnic (shank) portion of a ham, or back leg? Does the package also say "smoked"? Most hams do.
Either way....if it is indeed a cured piece of meat, then I'd follow the directions (which a higher temp of 325-350 are normal for ham) and go for an internal temperature of 155-160.
Make a glaze and put the glaze on for the last 1/2 hour and let carmelize.
is a great recipe for a double smoked ham (double smoked meaning it's already been smoked and you're gonna smoke it again to reheat it).