CR, just gone through the figures again and reckon you're right about the P/E to May'06 being about 9 given 8.1p EPS in H1. Given the traditionally weaker H1, plus some benefit to EPS from this year's share buybacks (and the director buying) MSI should be on for 18p EPS or better, i.e a P/E of 9.2.
With the large MOD contract kicking in next year we could hope for 23p EPS to May'07 and a P/E of 7.2. The thread title sums things up pretty well, as a 50% rise would give a P/E of 10.8, probably a bit conservative, but I suppose appropriate for a company unheralded in the City which just gets on with making money in its own understated way.