BUTTONS all work now!
So the seller contacted Audio Research and they told him that UPS most likely were not very kind to the shipping box. The outside of the box didn't really suggest that but if the box was dropped flat, there wouldn't be any real sign of damage on the outside.
They said that it is easy to fix this. The front plate just has to be loosened and adjusted slightly. I already surmised that this was going to be the fix after closely examining how the front plate is attached on my LS25 and on the REF 5SE. I was waiting for confirmation from Audio Research.
They gave the seller a procedure and he sent it to me. I couldn't perform the procedure exactly as described because my allen wrench was not long enough to get to the bottom allen bolts from the bottom. However with a little ingenuity, I was able to loosen the two top bolts and the bottom right bolt (from the top). I moved the plate until the buttons popped out.
I then plugged the preamp in without any connections and powered it up using the front panel power button. I knew we were in business when I saw the flashing 'MUTE ON' instead of 'MUTE OFF' during power up. Now, everything works as expected. I have not listened to it and probably won't for a day or so but I am sure everything is fine now - I hope.
