thanks.  works great now.  much less painful.

can I make a small suggestion?   Add a facility to the template metalanguage to include a file if it exists, and then use it to add ~/.pandoc/templates/preamble.<type> into your default.type files themselves.  the average user should not tinker with the default files when all (s) even if (s)he wants to include a snippet in the preamble, latex, html or whatever else.  This way, changes in default.<type> in future versions will continue to be picked up automatically.