Husband and friend bot hgreat handyman are at a standstill. They are restoring a home built in 1917. At some point the prevois owner laid a dirt filled concrete covered closed in porch off the kitchen area. The new owner would like this to be a dining area now , but the floor is 3" lower on one side. They are puzzled as to the easiest method to correct. pouring more oncrete until it is level , or shim the lower section with wood and cover with plywood then flooring. What is the best method.