Age of Mueller Climatrol?

Any idea on the age of this furnace?
Mueller Climatrol mod# M 119-175, ser# 8BY. I now it is Worthington but my chart does not have it. The 175 on the model number is the input BTU, but can find nothing on it (it is huge and really looks old). Any help?

All I have is a # 817-221-3259, not sure if it is still active.