Extremely, extremely tough to figure out which it may be through only photos. Are you working with an engineer? I would work with a plastics expert to decide which to used based on your needs. I used to work designing plastic processing equipment and it was amazing when I started out how one type of plastic can vary so much with look and feel. My advice is to understand the look and feel as well as mechanical properties you’re trying to achieve, and seek advice based on that. Having samples are a great start. There is a way to burn plastic and identify by smell, but I would highly advise against that.