Re:
Sorry for taking so long to respond to the original question. The answer is probably not. The shapes are different, on the pedals and the cleats.
I've dealt with customers who've tried to use SPD cleats with Nashbar pedals. They clipped in, reporting that it wasn't as smooth as with the original cleats. They unclipped by removing the shoe, removing the pedal, and bringing the shoe and pedal to us for separation. I can't remember whether we removed the cleat from the shoe or partially dismantled the pedal.
If you look at the reviews for the cleat, some say they work with SPD and some say they don't. I'm guessing that the guys who say it works have ridden with bad cleats for so long they forgot what good feels like.