(Engineer, Doctor, Scientist, Dentist, Lawyer, Chemist, Nurse - sure then you need a degree) but if it's MBA, Psychology, Art, Music, Philosophy, etc - forgetta about it.

So at this point, short of referring the matter to our lawyer, we’re not sure how to progress.

I'd be working with my lawyer on drafting the promissory note as there would be multiple lenders involved in this situation. 

-Do I involve a lawyer?

@Joao GuimaraesThanks Joao for all the insight and valuable info.Where may I find in Porto area a lawyer and accountant expert in RE ?

Crupi Law- increible lawyer.

Lawyer instructs to provide a 5 day pay or quit, to record the outstanding rent.

I’m not giving legal advice (I’m not a lawyer and don’t claim to be). 

If the seller files for bankruptcy for some reason, you have to hire a lawyer to protect your rights. 

I've got to find out if the remaining heir has a deed locked away somewhere in the Estate lawyer's office they used and I think Will Sifert is right that the property  might first have to get it legally transferred to the heir via deed but then again  the grantor in a Quit Claim Deed may not even be owner of the property, but in this case, including having previously talked to the Estate attorney, I know he if the only remaining heir that wanted it but now wants to surrender it as he doesn't want to pay the taxes and will never use it.