The National Electronic Code does not require grounding for older buildings that are grandfathered in, provided they are properly identified as such: either by labeling them as ungrounded or simply using a new 2 prong outlet to replace and existing 2 prong. 

@Todd GoedekeQRP is a broad term that applies to all Qualified Employer Plans of which there are many: 401(k), Solo 401(K), Profit Sharing,  403(b), etc.There are a few folks aggressively marketing under the label "QRP" or "eQRP" to make it sound like they have created something unique and fancy. 

I would label your project as gambling, not investing.  

If you are going to buy coin operated, look into commercial units made by alliance, their top line is labeled Speed Queen.

https://imgur.com/a/35tlOBzHi, I own a piece of property labeled "My Lot".

It's more about the expected nature of a chronic discounter and how it applies to the whole project when they cut the listing agent to a stump and offer garbage to a buyer's agent when they want to sell the property.

@John S Lewis  a few ideas, some easier than others...1) search lien records through the county2) check the system itself (panels and indoor hardware) for labels placed by the installer in case of service needs, pretty common, then call them up3) see if any neighbors have similar systems and ask them who they used, then call them up4) call local installers and ask whether they worked on that property5) looked up previous owners and ask them who installed, but check with installer about status rather than rely on the foreclosed party's representation6) Don't worry about it? 

I have found that money is all around you and it’s just talking about what you love to do and creating communities where other like minded people can join like FB groups and meetups.There are the five steps that have led to us raising millions of dollars.These 5 steps are imperative for doing it correctly, successfully and with investors in mind.Five steps to speaking with investors:1 Label who you are, what you do and what you’ve accomplished.2 Understand their needs as an investor.

Label each wire and hire an electrician to hook them to a modern large breaker box.IF your breaker box is a fire prone Federal Pacific get rid of that too.Doing so will give you great pleasure and reduce cost from 5-10K to a few hundred. 

Post clear instructions there. label things like extinguisher.and i doubt you cannot handle the rare situation "at work".