They probably came in at 36 to 42 inches. I picture Dwarves as being between 4 and 5 feet in height, with the males tending toward the upper end of that range.
Real swords are suprisingly light, usually weighing three pounds or less.
Even the large two hand swords are quite light. Those intended for use in actual combat generally weighed about six pounds or less. It is possible that the Sindarin and Dwarven systems of combat had some resemblence to each other. They probably came in at 36 to 42 inches. I picture Dwarves as being between 4 and 5 feet in height, with the males tending toward the upper end of that range.