David,
(and everyone else who is fiddling with the metabolic pathways) I have written
some documentation on the MetabolicPathways display and models where you'll find
a description of how to save a 'tweaked' display and the technicalities of the
models for the display. It's available thru the documentation server
(http://probe.nalusda.gov:8300/acedocs/index.html).
/staffan