Ive decided to order 4 @ 43mm blanks from real tone music in Australia, they seem to be the go to for a lot of things like this unfortunately not the pre slotted versions. So will be doing a bit of filing and sanding to shape, now not having the correct luthier files for the slots will test me, hence the reason for getting 4 blanks, I have trimmed pre slotted before using different grade sand paper and I have even used old strings for correct diameters with some good results. Can't justify the cost of buying the files but looking ahead and the work I have done without correct tools is something I may now need to look into. I will be keeping the old nuts I have a small collection of them now, will use those as a template.