Surly the GPL IS the correct licence for the symbols / footprints. The GPL would only come into play if you decide to DISTRIBUTE your schematics / PCB files, and if you were to do this then a copy of the symbol and footprint files would be essential anyway. If your designs were to stay internal to your company there would be no need to release your symbols to anyone outside.
Your finished PCBs could be thought of as a printed page, you do not supply a copy of your fonts and word processor if you sell a book! Steve
