Get him any knife you want... and gloves.Or castor oil flavoured nail polish.
He's not likely to become a daily carrier or aficionado, but as a nail biter he could probably use some scissors so I think any Victorinox that has both scissors and nail file. Even a Classic would be good for that, and you might be able to get limited edition scales that have something to do with his other interests so it would be special to him. If that doesn't quite seem right I would consider a Leatherman Wingman.
This is always a hard one for me when the person has not carried a tool. I'd think for the camping scenario theres alway a knife needed at some point? I'd go 111mm SAK. One of the OHO models would be nice for sure. If it adds scissor and saw that'd be cool.
Maybe attach a thin washer to a lanyard to aid in opening the other tools?