I have files associated with an old board design that I would like to have fabricated. These old files were generated using Mentor software. I have .pho gerber files for this design, but these files are gerber version RS-274-D and are missing apertures. It's possible that I also have the files that contain aperture information, but I'm not sure what I'm looking for. What extension are these aperture files and how do I open them? Are they ASCII files? Unfortunately, I no longer have the layout for this design.