A call to my Essex friends
 

Anybody smart enough to remove a ******* Allen screw that has stripped.
It had to be the one nearest and close under the hinge of the fuel filler cap.(749)
Tried whacking anti clock with a flat blade, tried to grind so I could use a flat blade driver but Can't grind propertly because of sparks etc.
Can only a see a quick spot weld of a tool onto it but who wants welding type stuff near the fuel tank opening

If it was me, I'd use a dremel with a very small drill bit - drill through the centre (v. Slowly) and it should then collapse in on itself... suck out the rubbish with a hoover. Works a treat!!!

Did think that but because it's the screw close to the hinge section there is no room

Take a picture as it might help with ideas?

what i have done in the past, if you have room, is to gently hammer a torque bit into the head of the allen screw it has worked for me ok.good luck.