Info derived from The New Langwill Index:
This is a guess based on the information listed...
1927-1950's, Selmer in the US had relocated to Elkhart (from Boston), and sold Elkhart-made instruments under several names including Selmer USA. The "Foreign" stamp was probably to identify it as NOT made in the US.
I don't see any reference to "Invicta" as a model name, but the name "Invicta" was a Swiss watch company from 1837, so I'm guessing it was European made but maybe not by Selmer Paris or it would have been labeled that way.
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As for the mouthpiece maker, who I had not heard of: (I highlighted the interesting part)
https://www.brasshistory.net/Bukur%20History.pdf
George J. Bukur
Cleveland & New York
1893 George John Bukur is born in Cata, Romania on January
12 (WWII draft).
1914 George emigrates to US (census). George Bukur, cornet
maker, #6003 St. Claire Ave NE, Cleveland (directory).
1915 George marries Anna.
1916 George is naturalized in Cleveland; #1556 E. 41st St.
1916-1918 George is not in the Cleveland directory.
1917 Daughter Anna is born in Ohio.
1920 Son George Jr is born in Ohio.
1921 George Bukur, instrument maker, #932 E. 76th St.,
Cleveland (dir).
1920s George teaches Vincent Bach mouthpiece making.
1930 George Bukur, musical inst, #1925 Barnes Ave, Bronx
(census).
c1934 George makes a trumpet mouthpiece for William
Vacchiano with a special backbore given to him by Mr.
Schmidt of Germany (Last Stop, Carnegie Hall, p.32).
(photo 3 is mouthpiece said to have been given to a
student of Vacchiano so possibly the same one)
1935 George is living in the Bronx (census).
1940 #8918 31st Ave, Queens, musical inst. repairman (census).
1942 #8918 31st Ave, Queens, self-employed at #800 8th Ave in
New York (WWII draft).
1959 George is the commander of American Legion post #96 in
Jackson Heights, Queens.
1960 George dies January 20th, buried at St. Michael’s Cemetery
in Jackson Heights (obit.)