That's rather cheap at 200$+. The Ebay norm is closer to 400$.
The transformer color code is this, yellow and black are the input wires (doesn't matter which is + or -) while the red and blue are the output wires and the green is the CT. You can connect directly to the yellow and black wires from the amp, thus bypassing both the switch and the PCB and you can also bypass the other side by connecting directly to the Stax plugs. If you have the black SB version then you need to connect the left transformer to the small trafo on the back panel or you get no bias.
If you want to do this properly it is best to bypass all of the crap wire Stax used and go directly to the solid core copper windings. You only have to cut the wax paper on each side of the trafo and push it apart to reveal the solder joints. Be careful with heat though as it will kill the trafo.
I have a few Stax trafos around from really bad SRD-7's that I scrapped for parts but they simply pale besides the transformers Koss used in the E/10 unit. The Koss unit is 4kg easy and the transformers are about half that. So if you can find one on the cheap snap it up and use the transformers.
Btw. This new SR-X Mk3 Pro I just made sounds really good!