Combining relay shields

About two years ago I found a schematic that showed how to wire an Arduino 4 channel relay shield with another 4 channel relay shield to allow the Arduino to control all 8 relays.

Does anyone know where I can find it? I have many Seeed 4 relay shields (v1.2) and I need to make a few 8 relay projects. I cannot find that info anywhere now. Any help would be greatly appreciated.

I am basically trying to find a wiring diagram that does this:

8-channel relay shield?
I offer one, control the relays with a simple write to a shift register, using SPI.transfer() or shiftout()
http://www.crossroadsfencing.com/BobuinoRev17/

8-channel relay shield?
I offer one, control the relays with a simple write to a shift register, using SPI.transfer() or shiftout()
http://www.crossroadsfencing.com/BobuinoRev17/

Here it is controlling strings of AC powered LED lights.