Needless to say, he is not currently able to manage his properties.The property is deeded to his son ( my fiancé' ) - can he act as the server of process/agent for him?

If not, you could hire a process server to find her.You can also hire a collection agency if you don't want to deal with it. 

I did get an attorney and had a 3 day notice posted by their server.

He then places that in a drawer that has a mail slot in it.  

But, that slot machine was just ready to pay out, she just knew it...and there was that envelope with all that cash in it in her purse...

You can hire a process server to serve the occupants, or you should be able to just post the eviction notice on the door.Note to landlords reading this: This is another great example of why month to month agreements are better than leases.  

While we waited for a slot I drove my son to the same company daycare in the suburbs $50/week cheaper and they had multiple slots open at any given time, Prob 1/3 of the families at this place were waiting on a Downtown daycare slot to become available.I would suggest to anyone to target a Detroit property in near Downtown/Midtown.

This notice is given to meet the requirements of legal notice to vacate and quit, and if said premises have not been vacated on the date aforesaid, suit will be brought against you for possession thereof.Name of Owner.Make two original copies so both have fresh ink.Sign and date.You can then deliver the notice in person, or pay a court server to do so.If she doesn't vacate by the date given, then have the lawyer start the lawsuit procedures.

The property management company  was horrid and I lost s lot of during the recession.  

It is very easy for you to take steps to remove it from the server and secure it on your system.