Nothing offensive meant about the broom, the hundred year old broom is a British Simile - it's 100 years old, but had twenty new heads and fifteen new handles! It applies to any "very old" piece of machinery which has had virtually all of it replaced at some time or another.
I don't disagree with you Lu, read carefully what I said about economics. The point was about general principles, which you seem to back-up. As it happens I've dealt with both Merlins and Rotaxes, but only the odd excursion in Lycontinentals which you probably know far better than I.
Sadly I haven't professionally been near a jet for 4 years (last one was a Saab Gripen) - and although I fly 60-100 hours per year, I am primarily an engineer by profession.
G