Thanks everyone. I get all of my rimu from the recycling centre at the council waste tip. Usually it is drawer sides or cabinet carcases but this piece was a bit of rough sawn tongue and groove that someone gave me. It cleaned up nicely with a hand plane but was only useful for something small. I wanted to give the flowers a little colour but staining a scrap with food colouring didn't look great so I decided on a coloured backer instead.
Rob