AFAIK this are the howitzer that fullfill my requirements
8 inch Howitzer M1: probably in combat since early '43, 90.7 kg shell, towed in 1 load so time to ready minutes, 16.9 km range, weight around 13 tons, lenght 10 meters
203 mm Howitzer M1931: in combat since Winter War, 100 kg shell, towed in 2 load, 45 minutes to ready, 17.8 km range, weight 17.7 tonnes, lenght 9.4 meters
21 cm Moerser 18: in combat since Battle of France, 113 kg shell, towed in 2 load, idk but think less of soviet howitzer, 16.7 km range, weight 16.7 tons,
Obice 210/22 modello 35: in combat since summer '42 (italians, idk for the hungarians), 101 kg shell, towed in 2 load (4 if need in mountain road), ready in 60 minutes, 15.4 km range, 15.9 tons,
B.L. 7.2-inch Howitzer Mk I to IV: in combat since summer '42 (?), 92 kg shell, towed 1 load so minutes for ready, 15.5 km range, weight 10.3 tons,
B.L. 7.2-inch Howitzer Mk 6: in combat since ? (if yes however not before of '45), 92 kg shell, towed 1 load so minutes for ready, 17.9 km range, weight 14.8 tons,
added traverse and elevation
M1: 60°, +65°
M1931: 8°, +60°
Mrs 18: 16° (360°), +70°
Mod. 35: 75° (360° taking out the stakes), +70°
Mk I-IV: 8°, +45°
Mk 6: 60°, +63°