In a very wholesome Twitter thread where tabletop RPG players shared stories of the most impressive props they'd seen during a game, Josh Sawyer of Obsidian chimed in with the time he played in a Fallout game run by Chris Avellone during the Black Isle days. Avellone gave each player a binder full of information that was kept updated during the campaign, full of info about the people and places involved.
As you can see in the first picture, Sawyer's character was "Arcade Gannon", a name that would be re-used for an NPC in Fallout: New Vegas years later.
Update: Avellone nicely shared some more of his "Paper prototyping" for Fallout. Van Buren was the cancelled Fallout 2 follow-up Black Isle were working on, some of which found its way into New Vegas.