Don,
Were the images large or tiny? (I heard you say you were using a magnifying lens.)
Was any of this, due to image size, just guesswork? (IE; "I'm not really sure what that shape is, but it shouldn't be there, so it's definitely mining equipment.)
Most of the photos were black/white and grey which means you have to allow for your eyes to adjust. I have several photos that are quite large however most were around 81/2 by 11 inches. The magnifying glass made it a bit easier to see the objects and detail. I scanned one and posted it here, the Kings Crater picture which has a number of very interesting things in it but it will not enlarge when you click on it ... which I thought it would. What I always wanted to do was to find a former military photo interpreter to peruse some of this pictures. If the TV thing ever launches this just might be the way to go.
Decker