Non conforming four Plex concerns

[Matt James]

I am managing a nice little four Plex with the opportunity to buy. It rents easily and has several long term tenants. The price and return are well within my goals. I have questions. The building was built in 1978. Remodeled into apartments in 2001. The work was done by the owner who is a licensed contractor. However no fire walls were installed at the time. It is obviously insured now but I wonder about moving forward. My commercial insurance provider suggest going with the current owners company. Which makes me think there is a risk or liability to owning  non conforming units. I would like to own the building but don't want to risk a law suit and loosing my other properties. Installing the firewalls now would make the return not work for me. I feel like they are using the building construction date not the remodel date for the policy. Does anyone have a property like this or any guidance. Thanks