Something else to consider (not that you aren't welcome here!) I'm not positive of the basenji % of my own pup!
The 50lb size and some of the other characteristics look something like these dogs - Carolina Dog. http://www.dogster.com/dog-breeds/Carolina_Dog
Here is the breed description which sounds like a great dog and also has some characteristics similar to Bs.
Just recently discovered in the wild, Carolina Dogs are still not a fully domesticated breed. However, these “wild dog” qualities blend together into a loving, cooperative and protective companion. Carolina Dogs are self-sufficient, intelligent and “pack” oriented, making them crave togetherness and family time above all else. They can be slightly reserved with strangers, but grow more outgoing over time. Carolina Dogs are great workers, herders and outstanding playmates for children.