(Mods: Please Move if this isn't the right thread...I couldn't find a "Items Stolen from luggage" equivalent)

In 30 years of flying, I had my first item stolen out of my bag today on MCO-ORD. While not expensive (it was a vest), it had a great deal of sentimental value. I am 75% certain it was stolen in MCO after checking the bag.

United baggage service told me they cannot open an investigation and offered me a $100 travel voucher as compensation. Couple questions:

A. Do I have any additional recourse or avenues to pursue?
B. Does the compensation feel in line with what to expect?