Auto generate textures?

I need to create >500 limestone blocks. I have come up with two limestone material node groups that each have 3 value inputs. Varying the values over set ranges produces a continuum of variations on each material. I would like to be able to instantiate blocks each with their own material based on randomly selected values for the 3 material parameter inputs. Is
there a script for that kind of thing?


Glandalf the senile

If you go grab this blend I made:

there is a node group called Object Variation
Try that.