Best (foodsafe) paper mache paste recipe? And other advice.

Looking good

Next to trim the edges,  do any shaping needed, and add more layers to top and bottom

J.E. Gordon points out that paper mache was used for fancy coffins for Pharoahs and for the drop tanks on fighter aircraft.  It just has to be kept dry with good paint and brief exposures to water.   He recommends the paper used for big bags of sugar and grain as the best to use.  He also cautions against the use of wood glue.  As with fiberglass, the toughness depends upon a crack not being able to penetrate a panel because the glue, 5 X weaker than the structural fibers, cracks at each layer, sending the damage off almost harmlessly.