My situation. I went to build some wheels and when I tried to insert the 2mm spokes I was using, they would not fit. Sometimes you have to screw them through the threaded part, but not this time. Will not accept 2mm. I found 1.8mm goes through fine. First time I have come across this. Pelissier 2000 (French) so somehow it figures. I am sure you can drill the holes larger, but should one drill them larger? Granted we are talking 0.1mm of material being removed and it is not like the spoke holes are right at the very edge. FWIW, the closest English size is 5/64 which is actually a bit undersize.
So how about it. Drill or no drill? Or don't be a cheapskate and buy new spokes.