I did look through some of the various lists of veterans on the web, and I did find a Lawrence E Robbins, who retired from the Air Force as a Master Sergeant. That may or may not be him. If you contact the National Personnel Records Center, they may be able to assist you further.
The National Personnel Records Center is the Federal repository of millions of military personnel, health, and medical records of discharged and deceased veterans of all services during the 20th century. Information from the records is made available upon written request to the next of kin to the extent allowed by law. They also have a procedure for forwarding mail to a veterans last known address, and if he was retired from the military, they should know his current address and may be able to get a message to him.