Mr jones is a posh person? Wanting to keep apearances, when being cleverer than others is the ultimate apearance for me! May be he doesn't deserve a RMH.
And aren't times tough anyways now? Ok, us economy is getting better, but how long another idiot banker does something stupid?
Well, now i'll stay on the technical side. Since i've thought thar one over before.
The first thing is to determin a spot in the living room, or area where jonsey and familly spend most of their time.
Then "embed" a J tube and mass into the floor.
I mean make the J tube insulated and all with the top of the feed tube recessed about one inch, below the floor, with a lip/rebate so you can fit a paver or cast iron grid on top. Make the heat riser go out of the floor, obviously. I'd say, he should do something like Sandy's bells. I am on the path of having a tall square metal box, which will be covered with bricks or pavers myself. But the same idea, replace the old barrel. Locate that against a wall, so it's not too noticeable. May be make that a part of a bar counter. That's posh!

Then pipe that to the mass into the floor/ground. The mass should be insulated below and on the perimeter. I was calculating lately, for myself, that something like 4 inches of Dow's floormate should do the trick.. And keep the heat within the mass to be radiated in the room and not in the ground. The junction between the floor edges to the mass is complicated to be insulated, so it's better to butt the edges. I'd use concrete for the mass, can be poured, and then the top can be surfaced and waxed. That's a posh finish nowadays in europe, waxed concrete. With a nice wooden floor butting against it. Should be good.
JMHO.