I've just had a look at Robe River Iron, TRS2004, and this sign shows in the Australia Trackside Objects menu as "Sign Bboard 10" etc. - there are a good many of them, often in multiples of five. What the abbreviation "Bboard" means I have no idea - but the strange thing is that "Sign Bboard 10" actually appears at the lineside showing "7.2", "100" appears as "72" and "138" as "99.36" - and changing between metric and imperial makes no difference!
Ray