I've sanded my folding kitchen steps/stool down to 320 and used some Norton's wool-pad to fine-sand. Given that it's going to be stepped on and used as a ladder, I was thinking of poly as a top coat.
What stains etc can you recommend to generally preserve the blonde colour of the radiata yet emphasise the grain? Do you recommend usng a sanding-filler and then re-sanding for pine?