I am not an expert, however I believe the answer could be found by working out the problem backwards. Developments with iron and steel progressed rapidly and significant improvements in materials can be documented with respect to the manufacturing date of the press. The historical development of ferrous materials, including cast iron, wrought iron & steel, is actually very fascinating. So first, confirm the exact date and figure out the processes in use at the time. Second, determine the location of manufacture, different countries and regions could develop slightly different processes. Then, if possible, do an etched micro-sample of the actual material, nothing works better than this, it is a well developed process. If you cannot get a sample of this press due to historic considerations, then find a similar era casting and extrapolate. Good luck. Dan.