I'm apparently missing something about converting an existing system to the SM. Copying the existing combined files and referencing them from the files that will become interface only, is easy. But all the layouts continue to reference fields in the original file. Using Layout Setup to reference the new data-only file doesn't change these existing layout references. Changing them all by hand is very time consuming. Is there a trick I'm missing?

I seem to recall that you need to change the file/table reference in the Relationship window. Once that's done, the layouts should reference the back end. It may take a restart of FM to be sure.

David