Completely random thought: Has anyone ever tried creating a light meter that would clip to the viewing hood of a Graflex SLR and try to read exposure from that? Or perhaps mounting a spot sensor to the underside of the screen, if that could be done without interfering with the mirror?

Yes, I intend to learn to expose by eye/zen. But this feels like it _might_ be a fairly straightforward hack that wouldn't require permanently modifying the camera itself.