Last Thursday I ended up getting an email from a complaints investigator at the DOL. He let me know that he believed that not having the zip code did not make my Report of Sale invalid, and that he had let the towing company know this information the day before.
At that time he also gave them 10 days to respond in writing. He also asked me to provide scans of the documents they’ve mailed to me.
Obviously, this is good progress, and I’m rather pleased to have someone looking into the matter in an official capacity. I scanned the documents and sent them along right away.
Now it’s been six days, and I haven’t heard anything more about it, so at this point we’ll wait out the remaining four days and see where we stand. Hopefully progress continues.