Just started playing with a project to improve the heater on the 4A. Got an old heater box to which I'm going to instal a new core and have acquired a minibus fan motor from the states. However I need to fit a fan to it. The originals are not available and wonder if anyone has found a good or better alternative before I try and track down an original. I want to build the new unit before taking my existing one out as there is always the risk that the blade will disintegrate on removal f