A most interesting bottling, but you have on the label about as much as I could tell you, I'm afraid. The unique things about it are its barrel-proof status and the fact it names Pennsylvania on the label. It conceivably could be from the defunct PennCo (later Michter's) plant, which indisputably provided rye whiskey for many labels.
Broad Ford was an early Overholt location, so it is very possible the whiskey is, indeed, 50 or 60 years old -- it operated in the era immediately following Prohibition.
When you say the bottle is 'signed by the president of the company', do you mean hand-signed, or that a script signature is printed on the label? In the latter instance, that is standard on Old Overholt bottles.
Here's a link with info about Pennsylvania distillers/distilleries: