The pic with the faux brick home made vent hood, the door with the counter top in front of it, the backslash with no grout and the spacers still in it, and the Formica roller on a hook, just WOW!

Last, I learned that if you buy a C vintage property (for example, built in 1960), but if you remodel the property to the studs in 2022 and update everything, including the wiring and plumbing, the right insurance company will use 2022 as the new year built which will give you better and less costly insurance coverage.

In my market, I see broker pro formas all the time that have a 35% expense ratio which is literally impossible on a vintage building with a single boiler/hot water tank.

Since it's 70's vintage, there may be MANY other capex issues not mentioned in your narrative. 

sf we do go by the sq ft and what the comparables sold for. in mf here in the US and florida for mf there are many ways to look at it. you can go by sq ft per unit for rent, we also look at what type of unit mix is there, what the upside is, vintage of the asset, the NOI and cap rate...i live in boca.. welcome to florida yalla be kef

There are lots of great single family housing stocks from the 1940-1950 vintage that sells for less than 80K (used to be 65K 1.5 years ago hah). 

@Mallikarjun Reddy Pateel as @Andy Eakes stated, you can look at the different OMs for expenses but sometimes those are projections or proformas from a broker vs actual expenses.There are report you can purchase for specific MSAs which have data from apartments by vintage and number of units.All of these should be a guide as the best source would be actual numbers from the seller and then you look for opportunities to improve income and reduce expenses.

It’s a 1960’s vintage, has parking that might fit 20 cars if done right. 8’ security fencing.

You could also do what a vintage trailer court in Bisbee, Arizona (The Shady Dell) did - put a vintage boat on dry land as an STR. https://abnb.me/2l8xN5qIKib

The complex paint job with the faux finishes?