Then I got out some of the red silks to try them out to see which matched best. The photos don't get an exact colour reproduction, but they give you the idea.
#119 seemed to be a bit too orange.
#106 was a bit too red.
But, #228 was almost right.
#228 is a tad dark, but given that on the design the inside of the inro would be in a shadow created by the top of the box I think this colour will work. It will be worked in flat silk with short stitch holding over the top as I don't want it to be too shiny.
So all I have to do now is get on with the embroidery, watch this space ...