Here is a list of usable (as in reasonably similar in appearance) factory pinball parts on Thingiverse found in a "pinball" search as of 1/14/2018. Not a bad list at all! Many aren't exact replicas but if you want to save money or don't care about the absolute details, this list will be helpful. It's also not all inclusive but covers at least 90% of the good models available.
Gottlieb C13150 Flipper Bat
Attack From Mars/Revenge from Mars Saucer
Sega Drop Target
Data East Drop Target
Stern Post
Gottlieb Lamp Cover/Plastic Nut
Bally/Williams Star Post
Addams Family Fester Chair
Williams Plastic Lane Guide
Bally/Williams Flipper Bat
Bally/Williams Jet Bumper Parts
Bally Drop Target
Bally Playfield Insert
Cabinet Leg Protector (Large)
Kickout Saucer
Light Weight Ball
Data East Flipper Bat (No Logo)
Bally/Williams Drop Target 03-8750
Cabinet Leg Protector
Bally/Williams Plunger Link
Data East Autolaunch Solenoid Pad
Rocky & Bullwinkle Hat Trick Mechanism Arm
Rocky & Bullwinkle Hat Trick Mechanism Rail Guide
Molex Pin Extractor Tip
Spotlight Lamp Reflector & Bracket
Bugs Bunny's Birthday Ball Ramp Protectors
Stern Spinner Washer
EM Plunger Parts
Solenoid Armature Link 03-8085 / 545-5293-00
Bally EM Chime Box
Chicago Coin/Hollywood Pinball EM Score Reel Wiper Arm
Chicago Coin/Hollywood Pinball EM Score Reel EOS Switch Spacer
Chicago Coin/Hollywood Pinball EM Relay Finger Support Bracket
Chicago Coin/Hollywood Pinball EM Ball Kicker 464-2514-R
Bally/Williams Flipper Opto Curtain
Bally/Williams Flipper Opto Interrupter
Apron Mount Replacement
Williams System 7 Corner Bracket
Millionaire Pinball Roulette Puck
Fire! Ladder Motor Trapezoid
Gottlieb Trough Switch Bracket
Williams Drop Target Catch B-11225 / C-11223-1
Gottlieb EM Insert
Williams EM Plunger Housing
Williams System 11 Flipper Bushing
Stern Drop Target Rest Ledge 545-6163-01
Gottlieb Flipper Bat
Gottlieb Drop Target
Bally Jeweled Posts
Allied Leisure PCB Clip
Bally/Williams Plunger Coil Stop
Stern Backbox Light Baffle
Party Zone Dancing Dummy Body
Williams Outhole Plunger Link 01-4251
