I do have a confession to make. When I first posted on this thread, I hadn't paid attention to the size of it. Thus, my comments mention this 'sword' (

). Now that I see that its a true dagger-sized implement, I still believe Span colonial. Even as such, it might have seen naval/maritime use. Love the thickened blade form.
Jim, have you ever come across a piece like this in your extensive research and many travels through the SW? BTW, hope you are doing well.