Originally Posted by HillRider

Great find.

Remove the chain and soak it in mineral spirits or kerosene to remove the old grease and dirt. You can use Simple Green or other water based cleaner but you have to be sure the chain is completely dry, inside and out, before reinstalling. Relube with the lube of your choice and reinstall with either Shimano's specific joining pin for a Shimano chain or a suitable width master link for any make chain. Do NOT reuse the pin you push out.

The grease in the hubs and headset bearings is at least 11 years old and may have dried out. I'd open them up and confirm the factory grease is still ok or relube if needed. The bottom bracket should be fine if it's a cartridge but should be checked if it's a cup-and-cone type.

The tires may be usable if the bike was stored in a cool, dark place away from electric motors but otherwise they are suspect. Probably worth replacing them if there is any question. The brake blocks are also suspect after all of this time.