Woodman - certainly possible on the components side; major structural assemblies would be original.
Cisco - who knows what they're capable of? The Chinese certainly have reverse-engineered aircraft and engines before; a JT3D would be an amazing feat, but their capabilities are tremendous. If such an item were to find it's way out into the West, it would no doubt be discovered as a fake quite quickly. The biggest danger is not really from complex mechanical items, but the parts within, such as bearings, springs and bolts. These are easy to reproduce, and look like the real thing. It's only once they're in use that their pedigree, or lack of it, manifests itself.
Many 'suspect' parts in circulation are good ones, it's just their lack of provenance that makes them technically worthless. If you have a 200 dollar bolt with no paperwork, it's just a lump of metal. The temptation is to make up an Airline Tag declaring it's good. Some outfits do this on a regular basis, which is why it's best to use only the Manufacturer, or an Approved Supplier with a good Quality Assurance department.In the same way as you guys know which Airlines are safe from a point of view of Operational integrity, those of us on the Engineering side can tell a good aftermarket supplier from a bad 'un, mostly by their reputation.