Fastened by at least 2 rows of nails and/or construction adhesive.

Smoking residue can sometimes be picked up this way, as well as in internal hallway ceilings (while you are testing the smoke detector of course).

There will be residual.  

When I was rehabbing multi-family we would trash any appliances that had the smoke residue on them.

The envelopes I'm looking at are on Amazon Prime for about 5 to 6 cents an envelope depending if you want them to be self-adhesive or not.

If the company is older and hasn't adopted new technology, does little marketing, or has new pricing opportunity, then I could quickly add some value to that business.I am also a realtor and getting my license in FL, so residuals can come from buyers / sellers.

Stay away from companies that have IMPULSE selling and try to get you locked into residual contracts that are hard to get out of.The companies I use for services I do not work on long locked in contracts and pay monthly instead.

The cash flow is comfortably paying the loan after expenses with some small residual.

@Jeffrey Kovnick The IRR is really just the cumulative cash on cash (CoC) return for the entire hold period, including the residual sales price.

I have see a miter edge beveled in a way that it is more flush together then secured with adhesive...