hex     decimal
---       --------
7D    125
76    118
6E    111
64    100
5A    90
55    85
4F    80
4B    75
47    71
43    67
40    64
3D    62
3A    58
38    56
36    54
34    52
32    50
30    48
2E    46
2C    44
2B    43
2A    42
29    41
28    40
: unit decrements down to
01    1

Effectively, above the half-way mark, the velocities are quantised so thinly we are dealing with two-thirds of a proper controller. It is a bit surprising that the keyboard manages to play as well as it does (one amateur's opinion, I have to admit).

This suggests that the keyboard response should be set so that most of the key output is in the 'filled' lower part of the range of values for maximum discrimination at normal (mp to mf) playing volume. The sparse upper part can then be reserved for less frequent ff and fff. The region of the velocity curve where this should occur depends on the player (controlled ff and fff needs strong practised fingers than mine!) and on the type of music that is preferred. Less problematic is what should happen at the low end - I  like to have null output at the lowest velocities, as you get no sound if you press a real piano key too softly.

Perhaps the following is a useful starting point:

Velocity = [6, 63, 76, 97, 119; 0, 96, 112, 123, 127]

Bowing the linear part of the curve outwards to make it convex will allow more discrimination at medium dynamics, but at the expense of control over pianissimi. Conversely, making the linear portion curve concave will allow graduated pianissimi at the expense of mezzo-dynamics.

Velocity = [0, 28, 50, 66, 80, 95, 110, 127; 0, 24, 50, 68, 87, 102, 116, 127]

Velocity = [7, 8, 111, 127; 1, 7, 103, 127]

I must say that I still think it's a little to easy to reach maximum velocity (127) but it sounds much better with the Pleyel than it did (and still does) with the K1...

Velocity = [0, 10, 24, 34, 43, 56, 68, 77, 87, 99, 112, 121, 127; 1, 8, 22, 35, 46, 59, 70, 78, 87, 96, 107, 116, 127]

Velocity = [7, 8, 113, 126, 127; 1, 7, 100, 120, 127]