Mine is the same, stem to stern Gates in 1965 with BC5p2, and phasor and all the associated gear and studios. (Still have some hollow state rectifiers around) A lot of it has gone, but the phasor and this Vanguard 2 aux remain. I've searched far and wide for a manual to no avail. I do have schematic, and that helps a lot. Mainly looking for the specs on the exciter, which is dead, and the input network to the tube.
Several have responded "Don't bother with it!" I probably won't, but it is the only aux I have.