David --

This happens from time to time. If you were able to see what's actually available at the National Archives, I'm convinced those files exist. It makes no sense that every source including last names starting with "L" for this regiment could all be lost. They just weren't filmed.

Something like this may have happened. Having just finished last names for this regiment starting with the letter "K", people responsible for microfilming records locked up and went home for the weekend. When they returned to work, no one was sure where they left off. Someone decided that "M" was the right place to resume, and away they went. No "Ls" for this regiment!