You can search permits for things like roof, HVAC, electrical and plumbing in there so can get a general idea if anything has been updated recently.Also, instead of counting on your agent to get info from the sellers agent (they almost never reply to questions like this) why not just have your agent walk the property to take pics and videos and let him figure it out for you?

There are a couple of mechanical/electrical/plumbing items to be aware of in older houses.1.

I've confirmed the price by quoting with more than 3 plumbing companies and even the city came out to make sure it wasn't an issue on their side.

Replaced the main water line and all gas lines myself from the meters using YouTube tutorials and seeking advice from experts at local plumbing supply companies.

I had 11 of these and good systems in place but still had 1-2 evictions a year and 3-4 big things that were normal annoyances like plumbing leaks, damages from hurricanes, or some vandalism.

There is a 1st year bumper to bumper warranty,  2nd year plumbing and elec, and a 10 year structural. 

I am in the plumbing industry and all looks good.

Do you rip out all plumbing and electrical or just patch and fix?

New drywall, majority new electrical, new plumbing, ac unit, windows, doors, subfloors, bath, kitchen everything new.

Do you know how the outside plumbing is laid out?