You will need:
-decent knowledge of securities
-name of the corporation and transfer agent (both found on stock certificate)
-access to corporate changes directories (check your local library)
Step 1: Head down to the library
Resources you're looking for:
-Directory of Obsolete Securities
-Robert D. Fisher Manual of Valuable and Worthless Securities
-"Survey of Predecessor and Defunct Companies" The Financial Post
-Capital Changes Reporter - Published by Commerce Clearing House
Any one of these books will be sufficient. In most cases these books are held in the reference section.
To find the value of our certificates, simply follow the corporation name found on your stock certificate through these directories.
Let's make our example Eagle Lock Co., 100 shares.
Eagle Lock Co. is found on page 594 of the Directory of Obsolete Securites. The book states :
"Acquired by Bowser(S.F) & Co., Inc. which name changed to Bowser, Inc. (IN) in 1943.
Each Share Capital Stock exchanged for $25 principal amount of Debentures due 7/1/63 and
0.5 share Common $1 par.
Bowser Inc. (IN) reincorporated in Delaware as Bowser Delaware 11/17/69"
Any reference to "Capital Stock" essentially means shares held in the company. So for this case, the origina 100 shares/Capital Stock were exchanged for $25 of Debentures(Bond type instrument) and 0.5 shares in the newly formed corporation. Now let's follow the newly formed entity:
Bowser Delaware Corp. is found on page 249 of the Directory of Obsolete Securities. The book states:
"Completely liquidated 7/2/70
Each Share Common $1 par and Class B Common 1$ par exchanged for first and final distribution of $18.60 cash"
The $1 par that is referenced does not mean anything in terms of this research. It used to have meaning in primitive capital structures although it is no longer relevant. It remains in a legacy law.
If your shares were lost during the time of the distribution there may be chance the distribution amount is still waiting. To look into this you will have to contact the company's transfer agent. Our next step will look into how to do so.
All of this work can be easily, quickly and throughly accomplished for you if you do not wish to undertake the effort. Stock Cert Expert's old stock certificates research package will identify the current status and value for $24.95. The above work could take 3-5 hours to accomplish - if you are unwilling to start your own personal scavenger hunt I would go with Old Stock Certificate Research here.