No "bottom" fixings required, on my mid 80`s +8 the centre of the fan is centred with the cross bar. The assembly is no more than an electric motor and a fan, no shrouding framework. The motor has fixing points in it`s casing.
Perhaps fan technological advance had to take elf`n safety into account and thus required the blades to be shrouded to some degree... dunno..!
I appreciate that the normal mindset is to utilise the fixings on the shrouding to mount the whole assembly though perhaps it might be worth thinking out of the box...? Looking at the second pic recently posted by Keith of his 4/4 four seater restoration project, it seems his has the original system, the fan being directly mounted to the water pump, thus no additional electrics involved..?
