It could be worth considering a shot at a software solution built for DIY landlords (1 - 15 units) to bring some automation to the rental management process, in turn, making things much much easier!

It would take a couple of days but it would be a permanent solution that did not depend on cooperation from the owner next door, would allow you to focus again on earning more income. 

Are there any solutions?

Thanks for the alternative solution.

Your solution assumes a person has time.  

The key is to find a lender that anticipates the problems early, and offers creative solutions.

Possibly regional banks would do, but the small locals will offer local solutions.

So the simple solution is to KNOW.  

He will probably use a quick claim deed and record the deed with the county.FrankArlington Funding solutions 

Also, if your plaster is loose your new drywall attachment means may be compromised unless you come up with another solution.