Little background about me -I currently work in banking as a "Performance Coach" training bankers and managers on sales, customer experience and career development etc in CO and AZ.

These customers tried to payoff with loans from other banks however no or was lending especially to mom and pop investors on 5 unit properties. 

It’s just a bummer because that’s a large customer base.

I have a small tool trailer that I customized to allow me to handle quick day or multi-day jobs.

Didn't take long before we found out one of our customers was in a squeeze.

Real estate is already an extremely litigious realm with serious past accusations of discrimination, and a database like this would lead to a ton of lawsuits against anyone who built it and its customers I can imagine. 

I would door knock and talk to these owners personally but its very difficult given a large geographic location of LA.Im going after residential and commercial apartment buildings.Any tips here will be greatly appreciated, Ive worked hard making hundreds if not thousands of calls and sent out tons of letters etc,no results yet, unfortunately I dont have a sphere of influence or past customers.

A method where instead of swapping cylinders, you only swap keys would be preferable IF it offered all the other features of the LLL solution (master key, Padlocks on same keying, Common entry lockset, similar customer support).I am not transitioning from LLL, but I see some benefits of the other method (getting rid of the extra cylinders).

I am about to pass $10 million in 2-4 unit sales for 2018 so would like to highlight the fact I specialize in 2-4 units, any advice for marketing materials?

First, a good attorney that does a lot of evictions is working on volume and return customers so they usually aren't very expensive.