why does everyone cut the slot by hand? I have seen an out of square slot that was 50mm wide and the "tongue" just snapped off, the cover I am working on had a 20mm out of square slot with the "tongue" snapped off, it has been filled in with alloy sheet and the new slot will be .05mm bigger than the blade, with a rounded end, and why does no one fill in the round hole, which I have done as there was a crack emanating from it, the slot has to go right to the rounded shoulder, leaving the rest very weak, and it didn't start out as the strongest cover on the planet anyway!
CLEM