Nell
Right. So the chair. First stage is really about establishing it as furniture before it becomes anything else — meaning for at least a week, maybe ten days, it just sits there being unremarkable. Living room, by the window, nothing under the cushion yet. Anyone who visits needs to register it as "oh that's been there forever" not "oh what's new."
Ivor's already primed to mention it to his mother like it's old news, which helps.
Once that's settled we move the actual thing into the base — I'm thinking the underside, stitched into the lining rather than just tucked in, because tucked-in gets found by anyone vacuuming. That's stage two though.
For now: nobody sits in it, nobody asks why, and if they do ask, it's "back's bad, don't want it wrecked." Simple.