Help! Analyzing commercial propert

[Tony Velez]

Can someone point me in the right direction on analyzing a commercial property? This property is from 1966 8 unit. It's been owned by the same family for decades. The rents are well under market value and the building is well maintained. The pro forma is for market rents not the actual rents. Even though they did follow up with an actual rent roll. I know we are not supposed to value a property from its potential NOI. How can I price this out accurate not knowing the a tail cap rates of the neighborhood? Any suggestions?

Thank you 

Tony V