Well. . . . . . .It could be a German conversion to a French Laffly W 15T, they applied armoured bodywork to some of them similar in look to their 3 ton Armourd Personnel Carriers bodies (the Sdkfz 251 3 ton SPW's).

The gun mount is a standard German item seen fitted on many bunkers, rail wagons, vehicles and trailers, its called Zwillingssockel 34, and can either have two MG 34 machine guns (as shown here) or two MG42.

R.