Are you by any chance using 5000 wet and dry to remove scratches in the lacquer?
Yeah I very gently hit a couple of spots with 3000 wet/dry but didn't really want to go too hard at it.
On modern paints you can wet sand / polish down to 1200/1500 grit and machine polish.
The machine I’m using is also new to me (normally use a dual action machine but this is a straight rotary so is taking some time to adjust to).
Happy with the results so far though - it's going to lift the bike definitely.
James