The real problem with stocks (phone/ railway/ and commodities) from the early 1900's is the depression. With mass take-over's, mergers, and BK's... very few stocks are worth the paper they are printed on for certificates dated pre 1922.

If you have a portfolio with Smith & Barney, Amex securites, ect... you can hand over the stock to them and have then evaluate the value for free. However, you'll never get that certificate back (whether it's worthless or not).