Hi heyhoop.
I too have the A70 with VE-jv1 expansion board. Indeed, it does have more than 64 sounds. What you have to do is press the (destination) "int" button and make sure the "patch" button is lit. You will then be able to change the patch for each of the internal zones. To know which one you are changing you will have to look in the display and see which zone is underlined.
By the way, what do you mean by "it says"? My expansion board didn't come with any literature. I got it in a plastic wrapper when I bought the keyboard. The store said that this is the way all of them are. Is there any way that I can get the literature? Perhaps download it from the web or maybe email?
Thank you
Jick