Dave Saul, of "Precision Music Rolls," did perforating for me.  The
paper was .0027" thick, fairly close to most roll paper that was used in
the heyday of piano roll making.  Dave bought it in bulk, which is the
only way they'd sell it, directly from the mill and shared the lot with
John Malone of Play-Rite Music Rolls, Inc.

Maybe Dave can directly comment on the paper mill's name, and what his
specifications are when he places an order.

Karl Ellison