Is there a store with an Internet front that specialises in theatrical props? For example, I have a hard time finding a human scull that would be photographically realistic unless a) get one from an anatomy specialist with horrendous prices or b) dig up the local cemetary.
I am looking for stuff I can use in a model photo shoot or still life but there are no stores with costumes and stuff around here and last time I waited for the greek carnival, nothing of quality could be found.
For the skull my question would be how much of it would be the image? If just handheld or sitting around in a scene, a cheap plastic one should do fine. Those you can get on Ebay dirt cheap.
Or you could get out the spade and see what Plato is up to....
Check a school. They often have skeletons used in physical science classes. They may consider renting it, or let you shoot the skll on site. If there is a natural history musem, you could check there, too.