Hi !!!
The link with a photo
http://1000aircraftphotos.com/APS/2610.htm
Type: S.M.75
Function: transport
Year: 1939 Crew: 4-5 Engines: 3 * 750hp Alfa Romeo A.R. 126 RC 34
Wing Span: 29.68m Length: 21.60m Height: 5.10m
Wing Area: 118.60m2
Empty Weight: 9500kg Max.Weight: 13000kg
Speed: 363km/h Ceiling: 6250m Range: 1720km
Load: 18 seats
http://www.samoloty.ow.pl/str130.htm
According to the link ( unfortunately only in polish ),a military SM-75 was equipted with 1 Breda-SAFTA machine gun 7,7 or Scotti 12,7 mm in an added turret at the top of a fuselage. Armmament of hungarian SM-75 was 2 or 3 machine guns at a top of a fuselage, bottom or/and from the sides. Besides, the tail wheel was modificated.The rear part of fuselage, fin and rudder had other shape.Additionally, during exploitation the Alfa-Romeo 126 engines were exchanged for the better Piaggio PXI RC.40 ( 990hp).There is no info about its bombload. Propably SM-75 didn't carry bombs.
regards