i too have an older model Craftsman with the big gray opener, and I used the manual settings for that opener, and the learn sensor on the second door. Didn't have any problems with the manual settings.
Thank you for your question Bruno. The KLIK1U remote control is compatible with Sear Craftsman garage door openers made in 1996. If you look up on the motor, you should find a colored smart/learn button. This is the button color to match when you read the instructions for programming the Clicker remote control to your opener. Use the left side of the page, for Smart/Learn button programming, and also use Chart A to find the number of times to press the chosen remote button during the programming. Sears Craftsman openers will use the Chamberlain information, so look for the color of the learn button for a Chamberlain, and use that information.
If you need any further assistance with the programming, or have any other questions,I would suggest contacting our technical support team at 800.528.913