Double and triple check with them regarding their machine room.

we bought in early 2013 for almost double the price of what it was in 2005/2006.

Market directly to the sellers.Be prepared to spend a lot of time and money trying to shake these types of deals from the bushes.Commercial properties seem to be a lot easier to get owner financing on then single homes and doubles.

For example, I could do a double closing for $160k to a buyer and $155k for the seller so that I would profit $5k. 

Talk some Attorney's in your area and ask them how to do a double closing.

http://www.biggerpockets.com/forums/99/topics/178575-looking-to-buy-in-area-that-will-double-value-in-1-to-2-years

In my area multi's, particularly quads, do really well and I get about double the cash on cash return out of a quad as compared to a SFR.  

Almost all will do Assignments although you might have to go over the assigned agent to someone higher who understands it.American title is the only one that will do a dry double closing but they want to know you're established.

They left a gorgeous 4-piece Bassett furniture set in the master bedroom, a second bed, a double-recliner sofa, two end tables, two lamps, a TV stand, and a china cabinet.  

You need an assignment of contract contract or you can use a standard purchase and sale contract and then do a double close when you find a buyer.