hello VintageRide,
your description of "the dustcap is round with no visible means of removing it" made me think of the atom 440 so i went back to the pictures of your bicycle. i recalled thinking they were eclair brand back when you began the thread on your new arrival. i still suspect this. do they say lyotard somewhere or is the identification a surmisal on your part?
atom 440 type dustcaps must be grabbed on the edges with a tool such as a channel lock or visegrip. alternatively one can raise the edge at one point with an awl or ice pick and then proceed to lift the cap out.
found this photo of one model of eclair pedal dustcap -
http://i.ebayimg.com/00/s/NTI3WDEwMjQ=/z/G5UAAOxyQyJRj~Hw/$T2eC16VHJGQFFhggHsFtBRj+HwOYiw~~60_35.JPG
i would expect eclair pedal parts to be pretty much unobtainium.
hope this helps you a bit.