I originally included gerber files but the preview looked very wrong (no holes), so I updated to just the Eagle .BRD file and then the preview looks good. This is for order 2017847 - apparently it's gone to the board house now, so we'll have to wait and see!
If I submit a board file built with Eagle v7.5 will it be OK? There was a note on the page about using Eagle v6 but I can't get hold of it. The preview pic on the order page looks OK...