Very nice! Since you've said that fitting everything into and rewiring the original can's bits isn't a concern/something you'd wish to encourage, I've re-thought the IIcx installation. Designing a new can to the mounting spec of the old wouldn't be a big deal. Galvanized steel, laser cut with perforations along the bend lines would make it a simple fab using a Big Box available seaming tool. Install own topped box with a large opening for plugging in your board as intended in the bottom could work out nicely. Are strain relief blocks for AC wires readily available?