Hi LL –
The firebox should be at one end of the boiler where the fire is (naturally!) and the smokebox at the other with the chimney. The superheater coils ought to be in the space where the gas burns or in some of the tubes, the 'products of combustion' travel along the tubes to the chimney drying teh stem on the way.
Some less powerful boilers take the steam and pass it through a couple of coils in the flame to dry it, though not intensly enough to be true 'superheat'. If your boiler is a simple cylinder above a firespace. this could be what you have.
Is it possible to take a photo?
And , yes, you probably are in the wrong section, but you have been found!
Neil