Hey There!
Important question ... why does the company have 80 websites? Are they being individually managed by the owner of each store, or are they all in the control of the central company?
If the latter, what you are describing is a strong illustration supporting the typical advice that it is generally better to build 1 powerhouse website for your brand than a large number of thin, weak, duplicative sites.
If this company was my client, I would be earnestly urging them to consolidate everything into a single site. If they are currently investing in maintaining 80 website, there's reason to hope that they've got the funding to develop a strong, unique landing page for each of the 80 locations on their main corporate website, and redirect the old sites to the central one. Check out how REI.com surfaces unique pages for all of their locations. It's inspiring how they've made each page unique. If your client could take a similar approach, they'd be on a better road for the future.
You would, of course, need to update all citations to point to the landing pages once you had developed them.
If, however, the 80 websites are being controlled by 80 different franchise location managers, what needs to be developed here is a policy that prevents these managers from taking the content of the corporation. If they want to each run a separate website, they need to take on the responsibility of creating their own content. And, of course, the corporate website needs to be sure it doesn't have internal duplicate content and is not taking content from its franchise managers, either. 80 separate websites should = 80 totally separate efforts. That's a lot to have going on, pointing back to the preferred method of consolidation wherever possible.
Hope this helps!