Here's another fantastic hockey photo from vintagesportsimages.com. It came to me with no date but three of the guys labelled, Red Kelly, Ted Kennedy and Harry Lumley. These are all easily identified by most hockey history buffs, as is the second Maple Leaf in the photo as Sid Smith. A couple other things are quickly noticed, the referee in the background is clearly "King" Clancy and the game is taking place at Detroit's Olympia Stadium.
A few other details allow us to narrow this down to the exact game this was from. Firstly, Harry Lumley was Detroit's goalie through 1949/50 (when he helped Detroit win the Cup) until the arrival of Terry Sawchuk the following year. Red Kelly began with the WIngs in 47/48 and "Teeder" Kennedy was certainly active over these seasons. However, Sid Smith wearing a number ending in "4" definitely helps narrow down the timeframe here.
Smith had been with the Leafs for parts of the 46/47 and 47/48 campaigns but wore numbers 22 and 16 respectively in those stints. He started wearing #24 only in 1948/49 when he suited up for only one regular season game with Toronto. He did however play six of Toronto's nine playoff games as the Leafs won the Cup over...Detroit. So this photo is from either the 1949 Stanley Cup Final or the 49/50 season, Lumley's last with the Wings.
This is when "King" Clancy comes into the picture. Clancy retired from playing early into the 1936/37 season and coached the Montreal Maroons for part of 1937/38. Clancy then became an NHL referee until the end of 1948/49 season. Clancy's last stint as referee was working the 1949 Stanley Cup Final. This eliminates 49/50 as the year of the photo and nails it down as the '49 Finals with Smith wearing #24. The four games of the final round took place between April 8 and April 16, 1949, perhaps the exact date of this game can be determined. A little bit of google newspaper archive digging turned up the boxscores of each of the four Final games, including the referees listed.
There we have it, the ref for each game were; Bill Chadwick in Game 1, Clancy in Game 2, George Gravel in Game 3 and Chadwick again in Game 4.
The photo has to be from April 10, 1949, Game 2 won by Toronto 3-1 at the Detroit Olympia. All three Leaf goals were scored by the aforementioned Sid Smith, the third goal assisted by Ted Kennedy. Having Kennedy pictured in all alone on Lumley in this photo could very well make this a photo of Smith's hat-trick goal at 17:53 of the second period.