K wrote:
The tuft is the normal new growth. It will continue to elongate into a
needle-clad branch, and the needles may change colour as they age
(typically get duller and darker green).

All the branches should be clad with needles, but most of them have
fallen off because of lack of water - presumably from when it was
abandoned. Sadly, they won't regenerate, but if you get enough new
growth at the ends of the branches it won't be too noticeable that the
'inside' of the tree is empty.

The normal growth pattern is that you start in winter with a typical
christmas-tree-like tree covered in needles. In spring it starts into
growth, and produces light coloured buds at the end of each branch
(sometimes a terminal bud and a couple of lateral ones). These open as
yours have to show fresh needles. The terminal one extends the branch
length, any lateral ones produce side branches. Over the summer, all the
branches extend, and the needles mature to become the same colour as the
ones already there.

Right, thanks, Kay. So, I'll prune away all the dead stuff, and then
give it TLC for a year and see if those branches lengthen and stay
healthy, or if the whole thing is only going to show signs of life this
time each year and stay basically looking "emaciated".

Eddy.