http://rockybergen.com/whatsnew/2018/11/30/amstrad-cpc-464-papercraft-20
If you don't find it, here you are: https://www.docdroid.net/1btVffs/amstrad-cpc-264-papercraft-ver-2.pdf :)
Maybe I'm just fussy, but with a little effort a few more of the angles could have been managed. It's a bit too square for me.
Bryce.