"I am NOT a candy maker or baker, and I didn't stay at a Holiday Inn last
night, so believe this if you want!"

If I recall when a recipe calls for cream, it's usually heavy cream, which
has more butterfat, but I can't give you the exact numbers. The brown sugar is
dark brown unless it specifically says light brown sugar.
Then again, like I tell my daughter when she asks recipe questions; A recipe
is just a guide and you are the chef. Feel free to change anything you want in
that recipe and don't worry about it. At the very worst it'll taste bad and
you'll know not to do it that way again. At very best it'll be delicious and
everybody will praise you. If all you have is light brown sugar use it. It's
still the same, just a lighter taste. Got 1/2 & 1/2 not heavy cream? Unless
you're going to whip it use the 1/2 & 1/2.
Be adventuresome in your cooking. Sometimes you'll just be amazed at the
good things YOU have created by just making little changes, and then the recipe
is your own!