Interesting! I did indeed scour the pasture with a metal detector, and came away with a bundle of brass locks! Pics (hehe) incoming!
https://www.flickr.com/photos/59011224@N04/So, after some examination, the Almont had been torn down, it basically came apart after I put a pick in it. (I'd like to put it back together!) The two keys to the Eagle, though differently bitted, open the lock, so I assume it's master keyed. The other two.... No idea. But they're really pretty after being polished a bit. No luck picking them yet, but I'm having fun trying. Yay finds!