Part of fenced in yard wasn't included in foreclosure.Find heirs?

[Amber Roberts]

Replacing fence and found out that portion of fenced in yard is still in previous owners name. Property bought 10 years ago in Allegheny County PA, as a cash foreclosure.  Property is 2 tax lots and since previous owner is deceased there are now 21 liens against property for back taxes (<$800). Spoke with a real estate attorney who said the shortcut way would be to find the heirs and have them sign quit claim deed and affidavit.  Anyone ever do this? I would pay off the liens and offer a small sum as the land isn't worth much. The land is inside our property we own, it isn't accessible unless going through either our owned portion of yard or a small portion of our neighbors. The attorney did find the paperwork from Wells Fargo with the foreclosure stating they did a good faith investigation to find the heirs back in 2007 and none came forward. 

I have found the names and hopefully correct addresses of 3 out of 4 of the children. Curious if anyone has ever done this? Can it be as easy as paying off the taxes and getting this signed? Am I overlooking something obvious that is going to bite me later? The lawyer also just mentioned calling the tax service, getting the pay off amount and just paying it and changing future address to go to me since there was already an investigation for our property that the children never claimed. We aren't planning on moving and could claim adverse possession (PA just changed to 10 years), but from everything I read this sounds like not a viable solution. 

Any advice would be greatly appreciated.