Dad’s 1969 Dodge Dart Swinger 340

re the hillbilly booth, best to use the fan to extract as when it's blowing in it can blow **** onto the job. just add a filter box in the booth before the fan to catch any paint. if you must blow into the booth fit a filter on the fan still as it'll hold dust from blowing on the job. you said there are 2 filters on the doors, normally the filter on the fan (extraction) side is 1/2 the size of the inlet filters. this reduces filter restriction to stop dust being drawn in round any edges that aren't 100% air tight.
neil.