A tricky puzzle from the past

My colleague, Bob Doran, recently ran across a link to some 1950s technology advertisements. It is noticeable that the advertisements are positive as well as being striking designs. There are not many computing ads. in the set. We have some nice examples of these on our own dept. website. One of the 1950s set, shown to the right sets a very attractive-looking puzzle. That's the kind of thing that is worth spending a few minutes with for the pleasure of figuring it out. But, be warned, this is a particularly tricky puzzle and the minutes can turn into many hours. Have a go, but in order to not waste your time and make you feel cheated, there are some clues given following the image.
The “icons” are completely misleading – the colour and glyph have no meaning. It is equivalent to the puzzle:

             x40x
xxx ) xxxxxxx
             xxx
               xxx
               xxx
                 xxxx
                 xxxx
                       0 

where each x can be any decimal digit. There are no leading zeroes and the fine-print clues are needed to solve the puzzle. Mean eh? Many thanks to Lloyd Thomas for figuring it out and providing a link to the solution.