I agrre that an atty may not be able to do much more initially but ... An atty, preferably an IP atty can explain all of your options, chances of success and how much it will cost in time and money. If you're serious, those are seriously worthwhile. Also, if you don't know what you're doing, you could conceivably damage your own case with amateur complaints/demands. INAL but this seems a bit different to me than just getting a website to take down something. These people have pretty clearly already started making money off your work in a tangible product. I wouldn't usually advocate enriching a lawyer but in this case, I think that would be the wisest course - probably wiser than seeking advice here - with no disrespect to anyone.

"Democracy is a pathetic belief in the collective wisdom of individual ignorance." - H. L. Mencken