Here are some kit numbers to help out:
AFV Club M102 105mm howitzer #AF 3506, 1/35 scale.
JB Models M119 105mm howitzer #JB1011, 1/76 scale. Two per box.
Italeri M101 105mm howitzer #319, 1/35 scale.
Revell of Germany 105mm FeldHaubitze #03014, 1/35 scale. Reboxed Italeri kit with modern German muzzle brake, taillights and Bundeswehr markings.
AFV Club Long Tom 155mm towed howitzer #AF 35009, 1/35 scale.
Peerless Max M1-A2 155mm medium howitzer #M3-600, 1/35 scale. Includes metal barrel, metal recoil cylinders, metal recoil springs and vinyl tires. Out of production.
Testors/Italeri M1-A2 155mm medium howitzer #232. 1/35 scale. Retooled to replace all parts with plastic.
Hasegawa Long Tom 155mm howitzer #31102. 1/72 scale.
Aurora 155mm Long Tom gun #308 (rectangular box) and #331 (square box). 1/48 scale. Out of production.
Believe it or not, I actually have all of these howitzer kits. I haven’t had the urge to purchase the resin M198, yet.