Take control. Dont let what you own end up owning you.
I did something very similar recently (as you will know Paul!) and at first I dithered and had my doubts one way or the other about letting stuff "that I might need" or was "too good/valuable" to go but when I did it was almost cathartic. Not to say anything about the much needed space it liberated too. And the extra funds.
Ultimately, its just stuff.