Keeping it simple, if you have an NES proto that i don't have, I want it.  My current list of NES protos owned is:

- Abadox -- Loose Natsume EPROMs
- Airball --  Unreleased Unique/undistributed build
- Alpha Mission
- Arcadia VI -- Unreleased.  Incomplete
- Archon
- Bad News Baseball -- Two unique copies
- Bases Loaded 2
- Battletoads
- Blaster Master
- Blues Brothers
- Boulder Dash
- Castelian
- Castle of Deceit
- Caveman Ninja NTSC -- Unreleased.  Released as Joe and Mac for NTSC.
- Caesar's Palace -- Different than the released version
- Chuck Yeager's Fighter Combat -- Unreleased
- Color a Dinosaur -- Extremely early build
- Color Dreams "Color Test Cart" -- Unreleased NES development tool
- Crystalis
- Darkman
- Digger -- Early Digger T. Rock.  Multiple differences.
- Ducktales 2
- Elite -- Unreleased NTSC version.  Single loose EPROM. WIP.
- Freedom Force
- Gargoyles Quest 2
- Hatris
- Hoppin' Mad -- (two identical builds) Unreleased
- The Hunt for Red October -- Insanely early.  Single looping level with completely different layout.
- Ikari Warriors 2
- Ike Ike Hockey (Crash N the Boys Ice Challange) -- Unreleased.  Released on Famicom.
- Iron Tank
- Kitty's Catch w/multiple builds-- Unreleased
- Klax
- Krazy Kreatures
- Low G Man
- Mag Max
- Magic Darts
- Mappy Land
- Marble Madness -- Set of four loose EPROMs
- Megaman 2 -- Different than the released version
- Milon's Secret Castle
- Monster in my Pocket -- Extremely early 1 level demo
- Ninja Gaiden III
- Overlord
- One on One --Set of four loose EPROMs
- Pacman w/multiple builds -- Tengen version with differences
- Power Punch 2
- Rad Racer 2
- Rally Bike
- Rampart
- RBI Baseball -- Licensed cart case with Atari PCB
- Road Runner
- SCAT
- Snow Bros.
- Solar Jetman
- Solomon's Key 2 NTSC -- Unreleased.  Released as Fire N' Ice for NTSC.
- Spy Hunter
- Spy Vs. Spy: The Island Caper -- Unreleased.  Release for Famicom.  This copy is in English.
- Star Trek V -- Unreleased
- Street Fighter 2010
- Super Gloveball
- Super Talking Jeopardy
- Super Turrican NTSC -- Unreleased.  Released in Europe.
- Tail Spin
- Temo Bowl
- Tecmo World Wrestling -- Two unique copies
- Terra Cresta
- Tetris: Tengen licensed by Nintendo version -- Unreleased
- Tiger Heli
- Tommy T's "Play Me" Sound Editor -- Unreleased NES music development tool
- USA Bowling w/multiple builds -- Unreleased.  Released on the Famicom.
- Videomation
- Wally Bear -- Early with noticeable differences
- Wacky Races
- Wheel of Fortune featuring Vanna White
- Zombie Nation

Shoot me a PM with a price you have in mind and we can certainly work something out.

Also interested in unreleased Genesis protos.