Try a fiberglass patch, if you have some laying aruond. Glass a peice or two larger than the holes directly to the surface over the holes. Use the quick bonding resin(10min apoxy) from auto zone. It cost about 3.99 and comes in some little tubes so it is easy to mix. It doesn't have to look pretty or anything, but it will work. If you want it to look good than you can sand it down, but I wouldn't. You can cover up the patch with dynomate or whatever so you don't have to see it.
That's what I would do.
