So..went back out and did a run checking to see if my earlier boost adjustment to the W/G actuator put the boost more spot on.
Results are;
from 2400rpm to 6600rpm
N75............Boost (mbar)
D/C............spec./actual
97.6 2040 1100
97.6 2190 1260
97.3 2520 1420
97.3 2510 1620
97.3 2510 1840
74.9 2510 2090
53.3 2500 2340
57.3 2500 2410
51.8 2480 2430
52.5 2470 2400
56.1 2460 2360
55.3 2450 2350
49.4 2440 2330
49 2430 2300
51.4 2410 2290
47.5 2400 2300
45.5 2380 2280
49.4 2370 2290
45.5 2360 2300
47.8 2360 2310
52.2 2360 2290
48.6 2360 2290
51 2370 2310
49.8 2370 2320
50.2 2360 2310
54.5 2350 2330
52.5 2330 2310
52.9 2320 2300
53.3 2300 2320
53.3 2290 2320
52.9 2280 2310
52.9 2260 2260
52.5 2250 2280
52.2 2250 2260
52.2 2240 2250
51.8 2220 2230
51.8 2200 2220
51.4 2180 2210
51.4 2170 2210
51 2150 2190
50.2 2140 2160
50.2 2120 2150
51 2110 2130
51.8 2110 2130
51.8 2110 2130
51.8 2110 2130
51.8 2110 2130
52.2 2100 2110
52.5 2100 2110
52.9 2100 2110
53.3 2100 2110
53.7 2100 2120
53.7 2100 2140
53.7 2100 2130