Wow! I was blissfully unaware of the differences. I generally go with the product mfg's recommendation on grades of sandpaper to use... but just now realized that on my last couple of projects the paint was EU while the top-coat was US.
Probably didn't/doesn't make a big difference in your scenario, but I thought "not all sandpaper is created equal" was a message worth getting out there. It was probably motivated to some degree by self defence also .

@Groovyman32 - It's good to see someone bravely take risks on their first build. Nice work!