One thing I'm not sure of after reading the original post is does he want the line marked and the corner found, or just the corner found? If he just wants to locate the missing corner, some of the above advice might work. There will always be doubt in the back of your mind, did I find the corner, or a piece of junk.
The post that says surveying is part art and part science is sort of correct, but its more 50-50. Its not really art, but more a matter of experience. I treat my surveyors license like its some sort of rare, fragile artifact. Its something you have to be carefull how you use it, or it will fall apart on you.