Dumerils Boa spurs look just like that. As for sexing, I prefer palpation rather than probing. I feel it's less invasive than probing. I need to make a video sometime showing how to do it. Basically, you support the tail with your thumb, then you run the tip of one of your fingers from the vent towards the tip of the tail. About 9-10 scales down you'll feel one or two bumps like BB's. That tells you the snake is a male. It's a little easier on baby snakes than adult snakes, but very accurate with practice. You could practice on one of your male Ball Pythons to see what it's supposed to feel like, then try it on your Dumerils. Most likely, your Dumerils Boa is a female though because of the lack of spurs. I'll post a video of the technique when I get a chance. Take care.