Modern Coins Or Banknotes Can Get A 70 Grading ! But What About Old Stuff ?

Hi I am new here and am an aussie collecting 1/10 - 1/4 toz gold coins worldwide and banknotes always aiming close to 70's grade.

So this applies to a banknote or a coin , my question :

modern coins and banknotes can get a 70 grading as gem perfect.

but what about collecting civil war banknotes , what is the general expectation of the highest grades for old coins and banknotes ; does anyone expect to see a Morgan dollar or old large currency graded as a 70 gem perfect ?

thus for each fifty years ; eg : 1800 to 1850 what would you expect as the highest'available / likely to be ? grade 45 or 60 for coins and / or banknotes ?

1850 to 1900 and 1900 till 1950 and 1950 to 2000 , you people have the knowledge and experience to give some indication of what would be the highest reasonably expected grades for both coins and banknotes , thank you ; crok ! ! !