A month and a half is more than sufficient time to adequately prepare for the PGRE!
I think the best and most basic way to study for the exam is to look at the previous papers. The PGRE is a very standardized test, so the actual paper too will not be too different in content or difficulty level from the practice ones given. The PGRE exam is mostly tests your speed at simple computations, eliminating the wrong answers etc rather than any in-depth thinking, so you need to be very familiar with the kind of questions typically asked.
The way I approached it was to work out all the sample PGRE problems from a particular topic, say classical mechanics, under a strict time-constraint. That made me aware of where my concepts were weak and what topics I had to study in greater detail. Also, this helped me in quickly recognizing what type of question it was and what would be the best approach to solve it quickly, so I didn't have to spend much time during the examination wondering how to solve it. For example, the special relativity section in the PGRE essentially consists of 3 kind of problems, given A & B, compute C (in various permutations of A,B & C)
Further, I also made short notes for every chapter I studied with all the relevant shortcuts and formulae, such as boundary conditions for electrodynamics, selection rules for QM, Energies of hydrogen like ions, important reactions in particle physics etc. I found it to be invaluable when it came to revising topics.
I don't think it would be very helpful to work through all the books you had mentioned. I think you should study only bare minimum the topics you need and focus more on improving your problem solving abilities under a strict time constraint. There are however, some topics which I think need a special focus
Classical mechanics: Small oscillations and Normal modes of coupled oscillators, Elastic and non-elastic collisions of rigid bodies
Electrodynamics: Applications of Gauss law, boundary conditions for EM field, Dielectrics, Polarization etc
Quantum Mechanics: Selection rules, Positronium!, Particle in a box with perturbations, symmetries, Harmonic Oscillator
Statistical Physics: Partition function, Entropy (S=k lnW )
Particle Physics: The first chapter of Griffiths book. Very basic questions are asked from it.
Also, if you have the time, go through the recent Nobel discoveries and inventions. There is always atleast one question about some Nobel prize related topic, like Graphene, 21 cm radiation etc.
Hope it helped!