There are some bits left, the pub on the main drag opposite what would have been the entrance to Hounslow aerodrome -the entrance concrete road is still there and can be seen in aerial photos of the time.
The tree lined approach to Heston is still there, as is, last time I looked, one of the old hangers. The whole area has been designated Aerodrome Area, with some 2d outlines at the approaches of a racing plane from the past -somebody else probably knows what it is!!
And the house at Hanworth Park is still in the middle of the airfield, as it was in the '30's, but surrounded by more trees!
Rgds
Mel