Hi Julian,
Was looking for that myself. I bought the 'Alfa Romeo Giulia - Spider Owners Workshop Manual' by Brookland Books and of course the late great Pat Braden's 'all alloy twin cam companion 1954-1994' and 'Alfa Romeo Owners Bible' available through amazon bookshop. The latter through the .com as only available in the good ol' US I found.
I missed a few on e-bay.. outbid in the last seconds
There's reference to 'CarDisc' (controversial) on the forum at the moment which might help?? Don't have the link.
All the best of luck