I'm no expert, but I would say they are probably mystics. Mystics look like low quality mojaves, they are a tad darker, and have less yellow. I haven't really been able to just pick them out by pattern, they seem to be more reduced than a typical mojave, but there are a lot of reduced mojaves floating around. Definitely buying from someone you trust, or with papers is the way to go. You can always contact the breeder and ask them if those are his snakes. He should have sales records and pictures.