Provided you made some small headed nuts and bolts as the nearest metric size is a bit larger and the heads larger still which can look wrong.
Most of the fixings are 7BA which would double upto 2BA but you would need to use M5 if converting to metric. Also its not just the fixings that will need altering you will have to adjust any imperial shafts etc that are threaded and the direct double up of the minnie looks chunky at the best of times.
J