I went ahead and installed the DBC unit yesterday. First thing I did was choose a place to tie into the console. The DBC box replicated the function of the scope's scan/raster generator that both drives the e-beam deflection as well as the CRT deflection. There is a connector that feeds the signal to the optional Dual Mag and X-ray modules that ties into the magnification control. I hooked my old Tek DSO to the connected and recorded the polarity, P-P, and offset values and replicated them in the DBC by adjusting a couple trimmers and a jumper. I took 4 lengths of RG174 coax with BNCs on one end and wires on the other and spliced those into the two wires leaving the board. Add one more BNC for the video output on the main board and I tie it all together on to the back of the DBC box. Make a few adjustments for contrast and brightness and I get this:

Woo, it works! This is a screw head on a sample stage clip and the edge of a dime.

This is a pic of the main control board:

X and Y waveforms: