You're completely correct LTNman when you say that lack of investment killed off SEN in the late 60s. A typical case of a Council owned airport who were happy to take the profits but refused to recognise that investment was needed if those profits were to continue.
Ah, the restaurant! They did things in style in those days.
What you say about the old terminal remaining virtually the same since those days until this year is basically true, but I think you would admit that no other airport in UK has seen the scale of transformation that is now taking place at SEN. It may have taken over 30 years, but what a place it's going to be by next summer.