Thanks all for the advice. The job is done.
The machine hire place didn't supply 100 grit.
24, 40, 60 and 120 for the belt and edger.
Trio had 40, 80 and 120
So I went up to 120 on the belt and edger and then back to 80 then 120 on the trio.
The floor at this point was silky smooth...