I tried aligning the green beam, elliptical as it is, to the arm by using the various steering mirrors after the doubling oven. The following was done:

1. Eric and I aligned the beam through the green Faraday - we levelled the beam using an iris to check the beam height immediately after the Faraday and a little further along the beam propagation direction.
2. We checked that the beam is reasonably centered on all the lenses. We changed the lens holder for one of the lenses from a Thorlabs model to a Newport model, so as to get the lens to the correct height such that the green beam was roughly centered on it. 
3. I then tweaked the alignment of the steering mirrors until the reflected beam from the ETM roughly coincided with the input beam. The return beam is getting clipped slightly on the way back through the green Faraday, so some more alignment needs to be done. However, given the ITMX situation, I can't align the arm to IR, so I'm holding off on further alignment for now...