Tom, I don't believe for a second you would drive that between the head and block of your Model A. But, yep that's a floor chisel! the floor chisel and concrete chisel are (I believe) are one and the same tool depending on who ownes it. A brick set (chisel) has a much different profile -- about a 45 degree angle on the cutting edge, they are used for cutting brick and block -- an art form that is going away due to diamond wheels. None of these tools should be used on a Model A. I have taken about a hundred heads off without a scratch; I use a block of wood and a BFH (4lb hammer) place the block under the front edge of the head and give it a whack or two -- it will pull away from the block, drive a couple of pre-made wooden wedges half way back to be used as a fulcrum to rock the head back and forth as you add more wedges. Works every time, and, it won't cost you a dime. So, if you have the money, a place to store the "thingy," and don't want to expend the energy, buy the $100 tool. Regards, E LaBrash