Will that work with vintage 70s yellow tile/tub as a possible way to inexpensively update from the original from yellow to white? 

I would also add the following:Has the sponsor done other deals of similar vintage assets in this market. 

These are small vintage buildings but we have fully renovated and updated all of the units and common areas. 

The acceptable vintage of a home constantly migrated to newer: for some aggregators starting at post 1950/1960 moving post 1980 to post 2000.

That discount as well as the vintage of the loans insulates the fund, in a sense, from fluctuation in market rates rising and falling.There is a correlation to investor desired returns and prevailing market interest rates and returns however in general the closer you are to market returns via market interest the more sensitive the investment would be to rate movement.  

New condo-like rentals with amenities will likely rent at a premium to your vintage two flat.

That said, you could try finding a smaller/larger home of similar vintage that sold within the past ~year in that neighborhood and figure out the square foot price.

@Kay FerdousWith that vintage of building, your wiring should still be copper, but could be aluminium - your building inspection would confirm.  

Depends on neighborhood and the vintage.

I think each vintage of house has its own quirks.