What can you tell me about this rearend?

Aaron and I finally cracked open the 8-1/4" rearend we planned to swap into his '74 Duster that is under construction. Here is what we found:



There wasn't any oil and a couple of bolts inside were loose. Its seems that a previous owner had been doing something in there, but I don't know what. I know absolutely very little about what's inside a differential, so here are a few questions:

1. Are there any good books or manuals on Chrysler rearends, similar to the one I bought for rebuilding the 727 Torqueflite transmission?

2. Does this number that is stamped in the ring gear tell me something about the ratio? 2852938-3.2 9 18 72 2

3. If the number doesn't reveal the gear ratio, can I determine it by turning axles or what?

4. What are tell-tale signs of wear or damage I can look for?

Thanks for any help,
Jerry