4plex with odd wiring

[Brent Hiser]

I am currently looking at buying an older 4-plex that has a sloppy electrical wiring system and we are unsure if any of the old knob/tube is still in use.  None of the units appear to have a problem at this time but adjusting anything in the future could be a nightmare.  Should I ask for money from the seller to update even if everything appears to be working now? Should I walk away, ask for a credit, etc? What is the best way to handle this situation?