I was able to find either LPS 1 or 2 by finding the nearest airport with a parts shop (in my case it was a Lane Aviation). I doubt you'll find it at a car parts store...
By looking at Yahoo maps, it looks like Elburn is pretty close to either Aurora or Du Page...do either of those places have a parts shop on the field? If so, that would probably be a good bet.
Sorry I can't be of more help
