Attaching plastic castings to wood

Years ago my family had plaster of paris castings made of our faces! I recently asked my husband to make a fancy board and attach the castings to the wood. The problem is the glue he bought "No More Nails" adhered to the wood but not the plaster of paris. Does anyone know what kind of glue we should use for this? Thanks Hollybagger2

Mary or Hollybagger2 I would use nails.

You've got to be careful not to crack the castings; you might try using:
~ 5 minute epoxy, you can get that from Radio Shack;
~ Liquid Nails
~ Dow Corning Silicone I caulk, which is usually used for tubs, but will cure using ambient moisture and form a good adhesion on porous surfaces.

Be careful with those originals; in fact you might make a mold off them first, then cast them in a resin which is much more stable that old plaster.