provided by Thackray Medical Museum, Leeds

date	item	source
1890	Estab. by G.J.A. Kirchner & H. Wilhelm in Stuttgart	Lohse
1910	Kirchner & Wilhelm, Heusteigstrasse 72a, Stuttgart, Germany	cat
1912	Kirchner & Wilhelm, Heusteigstrasse 72a, Stuttgart, Germany	cat
1917	Kirchner sole partner	BIOS report, p.29
1924	Kirchner & Wilhelm, 31 Schlosserstrasse, Stuttgart	cat
1925	Kirchner & Wilhelm, 31 Schlosserstrasse, Stuttgart	syringes, diag. eq. TCW, 5th ed. cat.
1945	Kirchner & Wilhelm, Heusteigstrasse 74a, Stuttgart	BIOS report, p.29
c.1953	Kirchner & Wilhelm, Heusteigstrasse 74a, Stuttgart-S	Lohse
c.1967	Kirchner & Wilhelm, Schlosserstrasse 31, 7000 Stuttgart 1	Lohse
c.1987	Kirchner & Wilhelm, Heusteigerstrasse 70a, 7000 Stuttgart 1	Lohse

Unfortunately all I can say for sure is that they have trumpets in the earliest catalogues we have (1910, 1912) but unfortunately the latest we have (1924) only covers syringes and diagnostic instruments. I would guess that 1890-1945 would probably be the maximum period for their production of trumpets.