Hi, I'm a brazilian graduating student and my current 'research' is related to this topic.. So I think we got commom business =).
I recently studied (sort of 'deeply') Klein's original paper (1926) and I'm trying to find Reissner-Nordstrom metric arising from such formalism by my own (not original , but still a challenge for my begginer profile).
I'm going to keep reading this topic and maybe posting some doubts (not stupid doubts, I promisse).
Nice work Norman =).
(contact: domingos_salazar@hotmail.com - please, i NEED to talk to other physicists.. ordinary chat and 'existencial' stuff +_+.. email me =D )