You did an excellent job crafting the plane.
Excellent write-up with great pictures and explanation!!
Just as a minor note about heat treating. Before quenching, the steel should be austenite which happens around 1475-1500 F. The Curie temperature is about 1414 F. This is not a big difference and using the Curie temperature is a good way of estimating the temperature and helps prevent over heating the steel.