The BFO section is pretty straight forward.
I used the supplied dumbbell core and some #28 wire. You will end up stacking some of the windings. The final inductance measured 10.3uh. Use one of the supplied binocular cores for the mixer transformer, T2. The last turn or so will be kind of a tight fit. If you can't get 13 turns on it, don't sweat it. Take a look at Wide band transformers in the Bitx and you will see why.
Your completed section should look like this.
The shape of the waveform is not critical. The distortion is caused by the transformer inductance. If you want to learn more about this, go to Wide band transformers in the Bitx