I received the connector bits I needed for the #3Dprinter repair over the weekend, and so connected my rebuilt hot-end this morning with good results.
Doing test prints now. Prob not a great idea to also be trying to dial in a new filament at the same time, but here we are. Assuming any probs are filament-based and not the new hardware.
Almost there. Had a sudden delamination in the middle of an otherwise pristine test piece. A try with a slightly hotter nozzle is underway.