Firstly, I am humbled by my woodworking skills, or lack thereof. Have only built the 36” THT and general vented MDF car audio style cabs in the past. I understood the difficulty rating was higher than other designs Bill has, but you don’t grow in your comfort zone.
The hardest part has been forming the throat sheaths followed by the horn sheaths as witnessed by all my missed staple shots. I used my commercial steamer to try and pre-form the panels (verified grain/flex direction) before installation which seemed to help a lot.
Side note - I do think I need to invest in a better table saw fence, framing square, and tape measure.