You probably know this already but just for the sake of anyone reading this thread who doesn't... regarding electrical: that 70A panel will need to be replaced, especially if it's Federal Pacific Electric (FPE) , Zinsco, GTE-Sylvania, Westinghouse, or contains any stab-loc breakers (usually with with red stickers) which fail to trip and are prone to starting fires. 70A is not enough for modern power consumption as it is, 100A is now the minimum per code, or even better upgrade to 150A or even 200A service since you have AC.

The bulk of my time and energy drain on this one was finding hardwood to best match 60yr old soft fir 'hardwood' flooring, figuring out how to blend old asbestos tile siding patches with something modern and the main drain and in-wall dryer venting. 

Copper/pex and pvc plus modern wiring plus good condition, then age in theory should not be a big concern.

If you're flipping the property I'd demo and rebuild the floor to modern standards with new materials. 

That's where we're at as a society -- hyperconsumerism mind control has gone so thoroughly in that the idea of figuring out how to get the jackboot of financial dependency off your neck frightens loan officers.

Pretty much all modern thermostats have a cool setting, no AC and it does nothing.

That's the modern version of apprenticing. 

After a thorough cleaning, I replaced all carpets; painted several rooms with modern colors & touched up the others; upgraded a few fixtures; and, made several small but impactful cosmetic improvements.What was the outcome?

If you want to be as close as possible to a big modern city, then Medford/ Everett/ Malden (I think Lynn is way undervalued too in parts) is your route. 

If only someone could find a way to build housing that the majority of the market is demanding (currently being supplied by older C and B class assets) they would solve a major economic/society issue and become enormously wealthy.