Actually the text says Bofors model 1928
Your photo's little oval with a number "622" makes me think it's from a Bofors sales catalogue.
Bofors product name, and each buyer would have their own service names and with minor changes
so in Sweden we had almost same gun with different designations in Navy, coastal artillery and army.
I been a bit cautious to identify anything as Bofors had a bunch of 7 - 8 cm aa guns, almost a version every year.
In Swedish Service
75mm Case m/05: (603mm long)
M/27 (Coastal arty),
m/27 - 30 (Army),
M/28 (Navy) (Twin),
Case m/30 546mm
m/30 S (Army),
m/40 (8 cm Army - or rather Bofors own AA "home guard")
Plus all export sales in 75 , 76,2 and 80 mm
Plus different fire control equipment (makes me a bit dizzy anyway)
The thing I do know is that Swedish armed forces did never have a M/29 (contrary to Wikipedia's entry)