If you were only able to reproduce it on a Nexus 5, I don't think analysis with ScriptObservatory will be easy. I'd still suggest submitting the URLs to be scanned by the robo-browser and then looking to see if what gets reported looks similar to what you saw before.

Also, if you write a Yara rule that matches on some of the unique features in the JS/iframes you saw, you could run a search through what's been seen. You can use that to also be alerted when new matches are reported. If something similar has been seen elsewhere, you might be able to tie it to a specific ad network.