If the Style I has an automatic roll changer in it then it's a
Style IX rather than a Style I, for the X designates the changer style.

For instance, a Style IXB would be a piano that has the automatic roll
changer plus a set of bells, the bells being indicated by the B in the
Style designation.

And the answer is yes, the roll changer does actually change the rolls
and, if enough credits are supplied, the piano will play through all
the rolls before repeating unless otherwise manually selected.

Hal Davis