I have seen Garand 10 pouch belts but I have an original 9 pouch M1 Garand ammo belt. It was my father's and he was a Ranger in WW2. It has 5 pouches on one side and 4 pouches on the other. On the 4 pouch side and in the place of 5th pouch there is a square, double thick section of the of belt material and at the top there is a provision to snap something onto the belt as there is a snap (like the one on blue jeans) present. Has anyone every seen one like this? I also have his original leggings and a complete, first-aid bandage pouch, complete with the original bandage in a tin box inside of it.
What you have is a M1918 Cavalry belt. The snap is to secure a double .45 pouch to the belt. Rangers and Airborne troops liked the belt because they carried .45's as backup weapons.