MGB window winder spacer

Pushes window winder handle inwards by 4mm so it doesn't rub against the door card. Makes windows much easier to open and close. Fits most MGBs but probably - not tested - a range of other 1960s-70s BMC models too as they used identical parts.

New version 7: redesigned in Autodesk Fusion not Tinkercad (as before). Result: the chamfer on the top surface is smoother and better integrated, and the thing is actually round, not composed of dozens of flat surfaces. Small improvements but worthwhile aesthetically, I think.