Yes you can add more hypertufa. You may want to go out and purchase some Concrete Bonding Mix or Agent , Looks like white glue, can get it at Lowes. Apply or paint on original hypertufa.
I have done without the Bonding Agent. But it should only help. It is used when you have concrete that you want to applyu a thin coat of cement to and want it to stick .

Take some photos and post

I will check it out. I may have something like it that a guy that put in out tile floors gave me. He had some of this cement, leveling cement left. Will that work or be worth trying? Being that I have it already? I will post pics I have to find a day to take pictures of a few other things, I'll try to get them all at once.

Not sure what you have, so it is difficult to tell you if it works. Bonding Agents will work - that is what I have used. Hypertufa needs temps at 50oF or above to cure properly. If you are in PA and zone 6 the temps have been low at night. I suggest that you move inside.

Good Luck

I have it in my basement, so it is okay. Lowest is about 60. I will take pics.

I finally have the pics. This is just the hypertufa, I will add the more cement looking coat over this. I am periodically adding moisture to help it cure before coating it with anything. {{gwi:74208}}