I've tested several dual primary transformers for lowest noise wiring configuration. Make the 2 striped primary wires LINE, and the 2 solid primary wires NEUTRAL.
The line and neutral markings should be on the IEC socket by the solder lugs. Follow Joe's excellent slide show.
Treat the two striped wires as one, and the two solid wires as one, for 110-120 VAC operation. For 220-240 VAC, one striped gets joined to one solid.
Hope this helps.
Right now your at the difficult part of the build, figuring out how to run the wiring. Take your time and don't rush it.
Basically, Line comes off the IEC to the tip of the main fuse holder. Then from the fuse holder shell to the thermo breaker, then back to the transformer line primary wire, or two striped wires in your case.
Your two solid neutral wires go directly to the IEC neutral lug.
Some of us use a 700 style terminal strip for the transformer connections on 400 builds, but it's not a requirement.
Thanks, that helps a lot. Have Eric's pictures saved also. Going very slowly as there is no rush for this.