I've spent years wondering where I could buy these! Now, just when I change jobs and don't have the need for them, I've come across them in the Rutland s catalogue. For those that understand, these are brilliantly useful and you will struggle to see them anywhere.
http://www.rutlands.co.uk/cgi-bin/psProdDet.cgi/DKWSE2||screw~extractors~@c~@b|0|user|1,0,0,1|3|
http://www.rutlands.co.uk/cgi-bin/psProdDet.cgi/DKWSE2||screw~extractors~@c~@b|0|user|1,0,0,1|3|