On the AutoTypist thread.  I have one with an operation manual which
describes several versions of the machine.  They were produced for both
manual and electric typewriters.  The simplest used the standard player
piano spools and had one letter per roll.  They were used for form
letters and the machine stopped at appropriate places to let the
operator manually type in a name,  address, or other personalized
information.  The AutoTypist for manual typewriters had a huge three-
leaf pneumatic attached to a cord to return the carriage.  (There were
instructions to punch pause holes in the roll after each carriage
return to allow time for this operation.)  The AutoTypist recently
on eBay was probably for an electric typewriter since it did not have
this huge pneumatic.  The versions using the large cardboard core like
an "O" roll stored many paragraphs (boiler plate?) on one roll which
could then be assembled into various combinations of letters, setting
up the choice of paragraphs to be used by pushing buttons on the
control panel.

David Sharpe