Any individual made a member of the Order for gallantry could wear an emblem of two crossed silver oak leaves on the same riband, ribbon or bow as the badge. It could not be awarded posthumously and was effectively replaced in 1974 with the Queen's Gallantry Medal. If recipients of the Order of the British Empire for Gallantry received promotion within the Order, whether for gallantry or otherwise, they continued to wear also the insignia of the lower grade with the oak leaves. However, they only used the post-nominal letters of the higher grade.
Who could wear a emblem of two crossed silver oak leaves? What year was it replaced? What was the emblem? What kind of medal was replaced in 1974? They continued to wear what the insignia of what?