If it was a 6 unit building it would have one roof and one foundation, you instead have 3 roofs and 3 foundations but it's not that different.

As you stated, appraisers are looking at square footage, age of roof, HVAC and water heater, electrical, foundation, windows, doors, year built, location.

The TSP works great, as they like that better for fund sourcing versus business funds.I've also handled certain aspects of my rehabs using 0% interest credit cards for things like flooring, appliances, hvac, foundation.

There may be issues with the roof, foundation, etc. which aren't visible from these photos. 

Then do you think foundation will go bad during the next 10-30 years?

Now is the time to check your investments and ensure you have a solid foundation that can weather the storm.

I'd like to be able to purchase more properties in the future, but I'd like to try and build a good relationship with a property management company to get a good foundation. 

We will de-title the home and attach it to a permanent foundation. 

I spoke to the township's zoning official to confirm I can maintain the existing units within a single family zone,   ( i guess that's grandfathering, not that word was never mentioned during our brief conversation)    I am trying to contact construction official regarding limits or restriction on renovations/expansion. because of your advise, now I will make him aware that this is a non-conforming property  (glee-asking the correct questions can avoid a serious error later) I recall at one time,  California allowed one to demo all but one wall and the original foundation and it was still classified as a renovation, but this is NJ not CA  Another thing i am wrestling besides not losing this opportunity if I am too slow to act, is my exit strategies.  

I think it will provide me the foundation, education and motivation to finally buy 10 rentals over the next couple years.