I think I've cracked it ...

0.5A + 0.5B = 72.1
A(North)+B(East) = 144,2

0.5A+0.5C = 71.0
A+C(West) = 142

0.5B + 0.5C = 72.9
B+C = 145.8

C = 142 - A
A = 144.2 - B
C = 145.8 - B
C = 142 - (144,2 + B)
145.8 - B = 142 - (144.2 + B)
145.8 - 142 + 144.2 = 2B
148 = 2B
74 = B (East)

C = 145.8 - 74
C (West) = 71.8

A = 144.2 - 74
A (North)= 70.2


That makes it all work


Edited to add:

Same procedure for slope returns the full data:

North Out - East In: CR 72,1 - Slope 126 - Par 72
West Out - East In: CR 72,9 - Slope 129 - Par 72
West Out - North In: CR 71,0 - Slope 126 - Par 72

East Out - East In: CR 74,0 - Slope 129 - Par 72
West Out - West In: CR 71,8 - Slope 129 - Par 72
North Out - North In: CR 70,2 - 123 - Par 72

__________________
//Mox
2008 bag:
Mizuno MX-500 460cc 10.5* Fujikura Tour Platform 26.3 stiff. (about to be replaced by MP-600 10,5* UST Proforce V2 stiff)
Mizuno F-50 3w 15* Fujikura Tour Platform 26.3 stiff.
Wilson Deep Red 5w 18* Graphalloy Fatshaft stiff
Cleveland HALO 3i hybrid 22* graphite regular
Mizuno MP-60e forged 5i-PW True Temper Dynamic gold R300 steel
Mizuno MP Black OX raw haze 50/6 GW, 54/9 SW, 58/10 LW
Heavy Putter B3-M
Titleist NXT Extreme