I have my great grandfathers top break 32 and was hoping someone could help me pin down the date of it's manufacture. It's an H&R top break 32, six shot, 3 1/4" barreland trigger guard is not plated. . Patent dates from Oct 4, 87 to April 7, 89. Not marked on the side of the barrel so black powder only. Serial number (from under the top tang is D 45231. Back of cylinder is stamped 231 Along the left side of the top tang just forward of the screw is a small protruding pin. I believe I have seen this listed as a second model, second variation. It has little to no value as the plating is about 50% gone and the cylinder and bore is less than pristine (to be charitable). I would never part with it as it is a family heirloom but I would like to know when it was made. And thanks for your help in advance.