This is another one that has been on a back burner for a few years. At a fall Gettysburg Show around 2015, I purchased a common CS Read-Parrott shell for under $200.00. I showed it to Carl and he asked why I bought it. What made that shell so special? I responded that from certain features, I believed I knew who made it and when. That made it worth adding to my collection and it rolls around on the floor at my feet as I write this. The first page below shows the shell in question. It has serious rusting, but all in all, what I consider decent condition. The perfect fuze plug is a modern replacement. The original was probably crushed and it was a common practice during the 1980s (and later) for dealers to improve the product for maximum return on investment. This thin-head fuze is typical of those dug at Gettysburg, Chancellorsville and Fredericksburg. It probably was issued with the thicker long-range plug seen on two of the following examples pictured below. Anyway, the real giveaway was the smooth rounded base knob, a distinctive feature of the Read-Parrotts stamped "AR" for maker Adolphus Rahm. I have the benefit of many photographs which I can compare and contrast. These unmarked Rahm shells are commonly found on 1864 battlefields and I've seen many for sale. Check your collection if you agree that knowing who made a particular shell and when is of interest.
The second page below shows another unmarked Rahm shell. Its stubby broken-off lathe key and horizontal mold seam on the ogive just above the shoulder are clearly visible. Apparently, Rahm's 10 pounders were cast nose-up allowing the hottest molten metal to for the rounded base knob where there are no air bubbles or casting sprues as are seen on many others. The flawed metal rose to the nose which is sometime notable. With an iron sabot, there was no danger of melting. By contrast, the copper saboted Reads had to be cast nose-down to allowing the metal to cool a little as it approached the cup sabot. Rahm produced thousands of these 10 pounders during late 1863 and 1864. Look around a buy one cheap!