My advice is not to waste your money on testing clean with bleach water and buy a mildew mold suppressant from hardware store it's a chemical you put in a pump up sprayer keeps mold from coming back if on a painted surface get a fungicide paint additive and repaint area.

I assume I’ll need to add fire suppression.

However the building has very good structural bones, and the boiler system, fire suppression, and elevators are all in surprisingly seemly good condition.  

The house looks like the start of a Hoard.The settlement also suppressed the case so tenants wouldn't have eviction on their records.

I don't see anything hitting commercial as far as usage goes until your building requires fire suppression systems.  

I thought the graph below from NorthMarq's 1Q21 Capital Report was interesting with the spread between major market and non-major market cap rates falling to the tightest spread in over a decade. Definitely have seen ...

Not only is it cheaper but with inflation and artificially suppressed interest rates the monthly payment is ~$600 less per month!. 

Hood systems/fire suppression also very costly.You mentioned long term tenants for all units, but what are current and historic sales for commercial spaces?  

@Lamont Marable find an investor friendly agent and you can get all of these questions answered for free from Someone that wants to earn your business.Adding units is extremely difficult if there is not already a fire suppression system in place or fire walls present.

This cycle continues to suppress available rentals.