Let's solve each expression step by step:

1) 19 x 85 + 15 x 19 - 120
= 1615 + 285 - 120
= 1780 - 120
= 1660

2) 25 x 17 - 25 x 14
= 425 - 350
= 75

3) 20 - [30 - [ 5 - 1 ] 2 : 2 ]
= 20 - [30 - 4 x 2 : 2]
= 20 - [30 - 8 : 2]
= 20 - [30 - 4]
= 20 - 26
= -6

4) 80 - [ 4 x 52 - 3 x 22 ]
= 80 - [ 208 - 66 ]
= 80 - 142
= -62

5) 28 x 77 + 24 x 28 - 28
= 2156 + 672 - 28
= 2828 - 28
= 2800

6) 174 : { 2 x [ 36 + [42 - 23]]}
= 174 : { 2 x [ 36 + 19]}
= 174 : { 2 x 55}
= 174 : 110
= 1.5818181818181819 (rounded to 16 decimal places)

Therefore, the values of the given expressions are:
1) 1660
2) 75
3) -6
4) -62
5) 2800
6) 1.5818181818181819