Grandfathers ww11 gun. Any help letting me know what kind of gun this will help as I know nothing except it's ww11 era

Unknown gun type

French soldiers of Leclerc's division at the Arc de Triomphe, Paris, take the view over battle casualties.  Best regards, JR.

Liberation of Paris, 1944 - grim prospect.

Full scale wooden mock up (note the man standing on the left who gives a good idea of the F1's size).

Twelve of these 140 tonnes behemoths were ordered on 27 April 1940 to replace the aging FCM 2Cs. This tank, designed to lead assaults on the Siegfried Line in 1941, was to be armed with a high-velocity 90mm gun (mv 710 m/s, penetration 100mm at 1000 m) in the rear turret and a 75mm SA 35 in the front turret (the mock up above shows a 47mm gun mock up instead) with a 25mm AT gun on each side of the hull ! The design wasn't finalised however and armament variants included a 105mm gun in the forward turret of in the front hull. Its front armour was to be 120mm with 100mm side armour and its two 550 hp engines would hopefully allow it to race along at a mighty 24 km