Commuting - Fender eyelets?

I am planning on mounting some fenders on my commuter, and was going to use some P-clips initially, but I noticed on the inside of the seat stays and the inside of the forks, there is a small hole drilled right about where a fender mount would go.
I then noticed on the Vanilla Bicycle website, that he was using these holes to mount the fender wires to the stays and forks. What exactly can I use to mount the fenders to these spots?

little allen bolts, after losing one that came with my fender set orignally, I was able to use an extra bottle cage bolt. But its dependant on whether the manufacturer had enough sense to make every hole-type the same size.

Isn't that a frame drain hole? Plugging that up might not be a good idea.

I'm assuming you are talking about vent holes used during the welding.

You may need to drill and tap those to an appropriate metric thread before they're usable. .. and then you might have to find the correct length bolts.

I have used plastic tie straps for this purpose. In fact, have a bike set up that way for 2+ years now. Almost as solid as bolt on but not quite. Wrap chainstay/fork with duct tape/inner tube to prevent motion from eventually abrading thru paint. Not pretty but it works.

I've used metal tubing clamps that had rubber liners. Wrapped around the seatstays nicely and held the rack quite securely. Make sure they are not too big as any play will scrape the paint off and eventually start damaging the frame if left unchecked.

I'm assuming you are talking about vent holes used during the welding.

You may need to drill and tap those to an appropriate metric thread before they're usable. .. and then you might have to find the correct length bolts.

The tubing is almost certainly too thin at a vent hole to tap for a screw.

I used these on my front fork.

http://www.wallbike.com/accessories/jpgs/pclamps.jpg

I also made it a point to buy stainless steel bolts and nuts to prevent rust.