For the record it appears that despite label differences the GPIO assignments are the same. So I am able to use GPIO 0, 14, 18, 19, 23 and 26 no problem. I can probally also use 12 & 13 as well.
This is good news for me because I had already hot-snoted my expansion dock in place and did not fancy pulling it apart again.
Edit: Of course the pins are the same the names are as the Omega 2 dock though, so 14, 23,26 becomes 46,2,3. Simple to correct and all works fine now. What a mess of wires though