The only setback is I do not have stable consistent income from my current job to even be able to buy a multi-family home. 

I personally wouldn’t qualify for a loan because I’m a 1099 employee and don’t have 2 years of consistent income history yet.

Kept natural exterior brick facade as-is with new energy efficient windows to keep the integrity of the home consistent with the neighborhood.

If you have more time, then do things like cold calling, door knocking, RVM's, etc.If you have more money, then do things like direct mail, PPC, etc.The #1 most important thing to remember is that you can be successful using any one of these but you have to be CONSISTENT. 

It sounds like you are getting the rent pretty consistently, albeit late.

Consistency and frequency of sending postcards is the key here.Hows the response rate of landing a home owner willing to work with you?

Appreciation is a plus but as long as the properties rent consistently if the market goes up or down I should be ok. 

@Dan Handford recently spoke at a conference about building those relationships and the importance of staying top of mind and getting in front of high net worth individuals with consistent value to them (not selling, just having conversations and you provide value).

In many instances a large portion of the rent is almost guaranteed to hit your pocket each month - again, this may not cover the full amount but they are consistent payments coming in (paid by the government).

(Marketing isn't rocket science but doing it consistently is apparently one of the hardest things in the world. ;)  This one is great on Audible, he has a good narration voice.For negotiation, I highly recommend "Never Split the Difference" by Chris Voss.