I got them from an Industrial Fixings shop and as far as I can see they are exact, even the 1970 screws fit. I have put a photo under stevesuk.
I have been slaving over another chassis today and it struck me that one of the most useful tools I have is a de-burring tool which is like a rotating curved blade allowing both sides of a hole to be de-burred quickly and cleanly. It can be used on aluminium to take off quite a bit of material, I opened up a hole from 25mm to 30mm today in a few minutes. I have posted a pic of the tool under stevesuk. The one I have is just a cheapo £3 or something ? $5 ? anyway, you can get them with different blades for different materials and more substantial, but you get what you pay for.


