Welcome to the Q&A Forum

I think you are on the right track.  But I would work harder at making more unique content for each of your geo targeted pages.  I go so far as to create a specific set of images unique to the city page all saved within a folder named after the city.  Then the alt tags for the images are city related.  It really doesn't take too much different content.  But I think that by creating / naming the images this way it sure helps eliminate the chance of being hit as duplicate.

I also insert the geo tags in the head section.  Some say this isn't important but I say it can't hurt.  It's one more spot to mention the city name.

I use the geo tag generator:  http://www.geo-tag.de/generator/en.html

I always put a meta description.  I do keep them less than 150 characters.  I agree that this is the call to action in organic rankings.  I love to ask a question that uses the keywords for the page.  For example:

Looking for Security Officer Training Classes in Houston Texas? Enroll today for Top Gun Security’s Level 2 security officer/security guard class.

or

Need a Houston Electrician? Call ProLectric an expert electrician serving Houston, Texas. For fast electrical service call 281-957-5514.

I hope this helps!

Another site now completely wiped of the SERP's this morning.

If it were me I would leave it as is. It is a legitimate link coming from a dealer web site.  I really think Google is baiting here.

Yes, I've had several hit hard.  A few are from the same situation that you have.  I'm hoping that the update has not completed yet and that things will raise back up over the next few weeks.  I can't see how this could be the "final product" ... at least I'm hoping.

Feeling your pain for sure.  I would start looking at the back link profile.