When they entered in service in German Army, Italians Semovente da 75/18 were designated StuG M42 mit 7,5 KwK L 18(850)(i). Semovente da 75/18 was the first self propelled armored artillery of the Italian army. It received the influence in design of German Sturmgeschutz III. At that time, Semovente received the appraisal of the strongest tank of an Italian army.

After the Italian surrender in 1943, some 131 Semovente da 75/18 were seized by the Germans and the production of another 55 was authorized. They were issued to six infantry divisions, two panzer divisions, three Panzergrenadier divisions, 22 SS Volunteer Cavalry Division Maria Theresa and one Gebirgsdivision intended for service in Italy and the Balkans. 

Here I leave some rare and interesting photographs collected from Internet:

A Semovente da 75/18 in Italy in 1943 clearly showing the 75 mm main armament (Courtesy Wikimedia - Bundesarchiv, Bild 101I-304-0614-15A / Funke)

Semovente da 75/18 with German troops in Albania, September 1943 (Courtesy Wikimedia - Bundesarchiv, Bild 101I-203-1680-12A)

The carcass of a StuG M42 mit 75/18 850(i) as photographed by a New Zealand soldier near Aquino, Italy. Several units employed this type of SPG in the area, although the most likely unit is Pz.Jg.Abt. of 71 Infanterie Division. This example has the four large teeth on the drive sprocket introduced at the end of 1943 in order to prevent thrown tracks. The front suspension has taken a turn for the worse and the rubber has been burnt from the surrounding roadwheels and return rollerd. Perhaps it ran over a mine. An internal explosion has blown away the roof of the fighting compartiment (Courtesy Panzerwrecks - Krueger Horst - Flickr)

Abandoned (with heavy damages to the running gears, the return roller is even missing) German Semovente da 75/18 in the city of Faenza, circa 1945 (Courtesy Panzerwrecks - Panzer DB)

Sturmgeschütz M42 mit 75/18 850(i) (Courtesy Flame of War)

Sturmgeschütz M42 850(i) in Italy, January 1, 1944 (Courtesy Panzer DB - Bundesarchiv Bild 101I-312-0968-24A)

Sturmgeschütz M42 850(i) with Zugkraftwagen 18-ton (Sd.Kfz. 9) in Italy, January 1, 1944 (Courtesy Panzer DB - Bundesarchiv Bild 101I-312-0968-26A)

Sturmgeschütz M42 850(i) in Italy, January 1, 1944 (Courtesy Panzer DB - Bundesarchiv Bild 101I-312-0968-09A)

StuG M42 mit 7,5 KwK L 18 (Semovente DA-75/18) attached Sturmgeschütz-Brigade 1 der Luftwaffe (later Fallschirm-Sturmgeschutz-Brigade 11) in Italy, September 1943 (Courtesy “Italian Armour in German Service 1943–1945” - FJR5)

Major Walter Gericke, Kommandant of the Fallschirmjäger-Regiment 11 in Italy, at the back StuG M42 mit 75/18 850(i) (Semovente da 75/18) (Courtesy FJR5)

Major Walter Gericke, Kommandant of the Fallschirmjäger-Regiment 11 in Italy, at the back StuG M42 mit 75/18 850(i) (Semovente da 75/18) (Courtesy Panzer DB - Bundesarchiv Bild 101I-569-1586-31)

StuG M42 mit 7,5 KwK L 18 (Semovente DA-75/18) from Panzer-Abteilung 202 attached SS-Sturmgeschütz-Abteilung "Skanderbeg", Slovenia, May 1, 1945 (Courtesy Panzer DB)

StuG M42 mit 7,5 KwK L 18 (Semovente DA-75/18) from Pz.Jg.Abt 278 of 278 Infanterie Division in an equipment exhibition arranged by the Vth British Corps, Forli, Italy, January 30, 1945 (Courtesy “Italian Armour in German Service 1943–1945” - Beutepanzer)

StuG M42 mit 7,5 KwK L 18 (Semovente DA-75/18) from 12. Polizei-Panzer-Kompanie, Budapest, March, 1945 (Courtesy "Az elsodort varos (part 1)" - Beutepanzer)

StuG M42 mit 7,5 KwK L 18 (Semovente DA-75/18) from 12. Polizei-Panzer-Kompanie, Budapest, March, 1945 (Courtesy "Panzerfahrzeuge und Panzereinheiten der Ordnungspolizei 1936 - 1945" - Beutepanzer)