Venerable Botty,
It wasn't the funding that I was thinking about. There's plenty of that available for Silbury (though a lot of time was wasted early on by people assuming that was the problem). Nor was it the BBC (although, by EH's own published account it seems there's a heck of a case for asking them to foot the bill)....

It was the simple thought that if a group of architects and engineers can draw up plans to rebuild a whole derelict pier in less than a year, and another group of engineers can build a tunnel to France in just two years, then a third group of engineers, perchance, could stabilise the holes in Silbury, without touching the archaeology or even needing to understand it, in rather less than four years.

The moment Silbury started to collapse was the moment it became an engineering problem of national importance and that's when the responsibility should have been removed from those who have non-engineering expertise and priorities. They can have it back when it's safe.