Alright, I just plugged it in, and everything seems to be in working order. Headphone and speaker out seem to be working great! There some noise in one channel, but it seems to be tube-related, since swapping the tubes switches the noise to the other side.
Just for my own learning... But why would there be such a large difference between what I'm getting at terminal 17 from the expected reading and still be in working order? The wiring category is for 115v - 130v, so I don't see how the fluctuation of my AC line between 120v and 125v would cause such a large.
Thank you very much for your help!