No scale model of the Solar System?

The masses would still all be in the right proportion, which is all you’d need. The time scale would, as WarmNPrickly suspected, be off, but it would be consistently off, so you could in fact speed up the film to make it right.

In actual practice, it wouldn’t even matter that much if the masses weren’t in the right proportion, so long as the Sun’s mass were much greater than anything else. Strictly speaking, everything orbits around the common center of mass, and the planets’ gravity affect each other, but that’s a small effect compared to the Sun’s.

For the mass/volume to be correct, wouldn’t the models need to be made of pretty much the same materials as the bodies we’re modeling?
That might be a problem for the Sun.