Fortunately it was not as tangled as it looked. Apart from a few places which had to be picked apart with the end of a dpn it just needed to be very slowly unrolled by hand. About four hours later I had this:
A happy ending after all!
It has come out pastelly, why does all my spinning seem to end up as pastels?! Actually, I know this is because of the mix of colours and undyed bits especially when it is spun super thin, but still I think I need to dye up some bright fibre.
It has come out a little thinner than intended, sock weight eludes me yet again. However, I think I can use it for socks, either on 2.25mm needles or I might have to buy some 2.0mm. They will be worked toe up until I run out of yarn, but first I need to spin the rest of the fibre to make sure I have yarn for the other foot.
It seems quite well balanced, in that it hangs neatly in the skein (when it is not twisted up to keep it tidy) but it is not a squishy as it could be so I think it is a little overspun in parts. This is quite handy for socks as it should make them a little tougher but soft and squishy yarn is still something I need to aim for.