Paul Mason has published a set of three texts on the life and teaching of Guru Dev.
These are available at http://www.paulmason.info/gurudev/gurudev.htm (see new book!)
I am in no way connected with the production of these texts and in no way benefit from their sale, but I wanted to let everyone know that they are available.
For me, there is a significant distinction to be made between the heuristic presentation of Maheshism and the far more traditional grounding of Guru Dev. While everyone will have to come to his or her own conclusion upon studying these texts, I know that Paul has made every effort to find the most meaningful translation and to supply every photograph and illustration available.