Hey David, just use JODconverter. You can read how to integrate it with OpenACS at
http://cognovis.de/developer/en/openoffice.
In your case you can make your life pretty easy and just get the openoffice wrapper procs using
svn co https://svn.cognovis.de:/projop/packages/intranet-contacts/tcl/oo-procs.tcl
In them you will find a procedure called contact::oo::convert_to_pdf_using_jooconverter and this is what you need to do the conversion. Everything else is "leftover" from tries we did when the jodconverter wasn't working as expected.
If you have further questions or need help, contact me please.