Bob:
The paste from Heinz is straight tomatoes, nothing added.
For the restaurants I mentioned, I would do a search in the American Style forum using "Heinz Tomato Paste" and you will see it come up under various discussions about the sauces for those two establishments. Those places typically added their own special blend of herbs and spices, but I do not recall if they used water to help smooth out the texture. I think some water was added, as no other tomato products were/are used in those sauces, but my memory has failed me on many occasion.

-ME