Okay, we need to replace two radiator's but the plumbing in this house
is pretty old, although that shouldn't present a problem. The main
thing is that the radiators are 600mm high and 1900mm long.

One has two pipes going into each end, the other has those two pipes
going into the right hand end - I need to know where I might find a
1900mm long radiator and if a single convector is okay for both. I
have not seen anything above 1600mm (I think).

Any help is appreciated for this newbie.