Well, here is some pics for ya.

I lucked out and was able to reuse most of mine after a repaint.
And I was able to get some more from a junkyard car 3 years ago that had some still on it.

Unfortunately I don't know who is making them, but there are some large fastner companies out there.
As somebody said, you might try a local paint supply shop, as they might have a book to look them up or maybe have some pictures or better yet a display board with different fastners on it.

And the rear wheel trim, on the very bottom ends should have holes for screws. I thought it was weird that it was done that way.

Oh, I don't suppose that where you found your trim, that they might have more? I could use a set of rear wheel trim.