Thank you, one and all, for your input... Neutral or otherwise.
Didn't know about the doorbell transformer but learned something new. I'm hoping that's the only source of the warm-plastic-and-old-wood smell that's been puzzling me for a while until I felt around in the meter 'n' fuse unit for anything overheating. The transformer is the only warm thing in there; seems hotter than I'd expect (though I'm not sure how warm it should be under normal circs, knowing it's a transformer).
Here's hoping the home insurance emergency cover can replace it - or at least isolate it as a potential fire hazard.
Thanks for appreciating my late father's fuse wire collection. There's also a piece of candle in there, a cutter and a lighter. My father was ever-practical!
I'm also glad to have kicked off a thread within a thread concerning wiring layouts.