I've seen someone (rightfully) try to retrieve Grandma's jewelry, favorite rocker, china service, etc.

I'm kind of leaning towards first reply, just junk it and get a top hanging slider. trying to save outdated and vintage mechanical trinkets is a lesson in futility.

Take away all of the “big stuff” like plumbing, electric, HVAC, roof, etc. and there are still plenty of 70’s buildings out there with original kitchens, groovy faux wood paneling, popcorn ceilings, really small closets, etc.

@DongHui Patel that will vary greatly based on the property size, vintage and local market.For certain markets, you can buy data (from Axiometrics, etc) that shows the average expenses by property size and vintage.You can also ask the local PM companies you plan to engage.What size property is this?

My cell phone company, jewelry store credit account, etc....

The other is that the huge consumption of gold for jewelry in India, China and the Middle-East is growing rapidly as their economies grow.

Brie Schmidt pretty familiar with that Chicago vintage and concur it is likely due to antiquated cast pipe or its layout.

No one has figured out how to sell art, jewelry and other unique products online. 

If there is no one around to water the pots, you could always do some "faux" plants.

The problem with your interpretation  is that if a tenant mistakenly or otherwise left behind something of value e.g valuable jewelry, then the law as you state it would allow the landlord to claim it was abandoned and convert it to his own use.