I have an original 81a myself.  
I bought my machine 5 years ago for $2,500.  The machine had lived indoors it's entire life and was in very good/excellent original condition.   
Perhaps I overpaid at that time, but it didn't matter to me.  I could afford it and it was exactly what I wanted; an original, unrestored Vendo 81.
I have no clue on what the current value is on an 81A.  I
Good luck.  
