Here are some of the places I like and use to source parts and manuals for pinball and arcade restorations.

Pinball Resource – http://www.pbresource.com/

Pinball Resource owns a large stock and rights to reproduce Gottlieb parts and is a great source for many other parts as well.

Marco Specialties – Marco Specialties

Marco has a great website and parts inventory.

Big Daddy Enterprises – www.bigdaddy-enterprises.com

Great electronics parts source.

Boston Pinball Ebay Sales History – http://www.bostonpinball.biz/

Record of Pinball sales on eBay with Prices