Beautiful set up, but I can see from the picture you are not going to get much heat radiated into the room or space, most will just rise to the top near ceiling, what if you were to buy those maplin radiator heat booster, and mount it under the rads so that it sucks air downwards, and distributes into the room at lower level, this should really make a lot of difference, it would certainly be worth trying, for that price, all depends if it can move air all the way from top to all the way to the bottom, which means you may have to block some of the gaps between fins, and sides so that the fan blower only sucks air from top and as the air gets drawned in from top, it picks up the heat from the radiator fins, and warm air is then then blown across the bottom of the room. A sort of warm air heating like system, as it is I can see its not going to help much in heating your lower part of the room.
Secondly you might have been better off mounting the rad in that kitchen corner facing into the room rather into the kitchen.