I believe those are Motorwheel Fleas - they were made of magnesium just like the Motorwheel Flys. I have only seen them once. I bought 2 sets of flys off a guy in Dayton OH and he also has a set of Fleas for sale. I didn't like the looks of them and passed ( yes, I'm an idiot).
When i looked at them closely, they appeared to be Flys that didn't have the slots cut out yet.