Unless it is in a historical district (which has its own list of hassles and complications that should be considered) or it ancient I wouldn’t think of it much differently.  

So, right after 2007 the bottom fell out and it was really bad for what felt like forever, but within a decade the market so thoroughly "healed" that it was well above the pre-collapse heights.In the words of some ancient Chinese proverb, or @Brandon Turner, "the best time to plant a tree is 30 years ago. 

or  are these ancient pads made for when mobiles were 50' long?

Leases were ancient.

Fieldstone foundations, knob & tube wiring, ancient HVAC, decrepit plumbing, moisture, mold, etc.

If you get one of those all-in-one printers that has a flatbed scanner on top, possibly with a document feeder for when you do want to scan some 8.5"x11" stuff - like the signed version of a lease - that may work better for you.I have a really ancient HP flatbed scanner with a document feeder, and a separate ancient HP LaserJet printer, and those have worked for me so far, but I only have one SFR. 

If they are not ancient and can be spruced up quickly and easily (new flooring, paint, appliances) then you should sell them quickly. 

Hi BP members,My name is Amr, I’m 42 years old, living in Egypt and planning on starting Real Estate Investing in Canada.I’m interested in the BRRRR strategy of holding and renting, till now I can’t make up my mind on where to start investing.

Look at any major architectural feats, the creation of ancient empires, historic works of art, and even the rise of Facebook and Uber; they were carefully and intentionally planned.

The outdoor condensing unit looks good, but the interior unit looks ancient.