I ended up finding three mentor texts after what seemed like hours of searching the web. We read the three texts (I read, they followed along for the sake of time) with the question "How do writers convince their readers to agree with them?" in mind. Through a series of turn and talks, as well as small group discussions, we came up with this anchor chart to guide our thinking.
The other chart we made from these mentor texts was what we noticed about author's craft in the three pieces. This process was much harder for them. They struggled "reading like a writer" as opposed to reading the content of the pieces. After much conferring, collaborating and guidance we came up with this chart.
With these two charts as our checklists of sorts, we set out to create our own persuasive writing pieces to support their various problem solving magnet creations. If you are super interested in how they turned out, you can read them (after March 3rd that is!) on our blog here.