You Canadians don't blow your own horn often enough the way the Brits, Russians and we do. I continually see aviation programs touting the DeHavilland Comet as the first jet airliner, when real aviation people know the Canadians did it first. Another thing overlooked is Henri Coanda and his ducted fan flights as early as 1910. Of course, the Russians did everything first and the biggest.
A bit of history, nothing newer than mid 1942 as near as I can tell. Several of the flight line shots are at the same base as the hangar roofs are distinctive. A few more to follow.
This is likely the same E model as just above with no meatball. Joe Baugher's site tells us 41-2599 was delivered to Lowery 26 Feb 42, then to 19th BG, then to 43BG, was in battle of Midway and ditched at sea 16 Jan 43.
This is likely the day for the first flight judging by the crowd of workers watching. Most sources say it first flew 14 Feb 42 but some say 26 Mar 42.
As has been stated above a number of the aircraft photographs were taken at the same location, the Selfridge Army Airfield on Lake St. Claire in Mt. Clemens, MI. They are 28701: P-35, 28705: P-39D, 28725: P-39D, 28731: P-40B and 28706: P-40B.