Hi olivigus
It's marked "Made in Switzerland" on the back
Your "Hohner Verdi IIN" was most probably manufactured during the 50'-60' by the Swiss factory "Accordina AG", in Alstätten (Sankt-Gallen).
(The location is on the Rhine river close to the Austrian border and almost opposite to the city of Dornbirn (Vorarlberg, Austria).
The "Accordina AG" company was created in 1943 as a jont venture with Hohner Trossingen (Germany). The idea was to facilitate the accordion distribution in some sensitive countries during WW2.
The "Accordina AG" company (not to be mistaken with the "Accordina" CBA harmonica mouth organ) acted as a factory (mainly using accordion parts from Hoihner Trossingen) and as a distributor with the 2 brand Hohner and Accordina. They mainly produced CBA (few PA) for the european market. The "Accordina AG" company did officialy close in 1968, but to my knowledge a revival workshop continued until the 80'.
You will find some more information about your "Hohner Verdi IIN" on page 8 of this pdf :
The "Accordina AG" company produced many CBA models under the Hohner brand like "PIccolo", "Riviera" and other models under the Accordina brand like this "Accordina VII" :
The RH "golden" register switches were typical for the 60'.
RH : 5 rows flat kb., 4 voices (LMMM), 7 switches [:]III[:] LH : 120 std. bass, 5 voices, 3 register switches :
akkordeon-museum.ch
THis "Accordina VII" was also availlable as "Accordina VII S" (red colour) :
The RH "black & white" round register switches were typical for the 50'.
RH : 5 rows flat kb., 4 voices (LMMH), 11 switches [:]III[:] LH : 120 std. bass, 5 voices, 6 register switches.
Another "Accordina" "wood" country model manufactured during the 80' :
RH : CBA (5 rows flat kb, C-sys), 38 notes (no silent button), 2 voices (LM) with cassoto [:]III[:] LH : 60 std. bass 5 rows (2x bass + maj. minor, 7th chords). (NO tonic note in the 7th chords => able to play diminished chords : eg. Gdim = G Bass + C 7th chord (E, G, Bb).