I'll try and drop of the stuff before I go to perth on friday.
Hey I asked around about the grazing angle! The grazing angle is the angle at which the grating is the most efficient, ie. reflects the most light. At the moment you are using a grating that has a blazing angle at 240~280nm I think (in the UV range anyway). So if you find the you don't get enough light in the red, then you can change the grating to one that has the same number of lines per millimeter (resolution) but has a higher blazing angle. The exact type that I happened to have accidentially not thrown out this week.
Unfortunately I don't know what to do about the resolution problem you are having. I found the old dual sided 600/1800 lines/mm grating I was looking for a month ago but they are to big to fit in your spectroscope and they are quite badly scratched.
I think one of them was even drawn on by someone.
