The shoulderboards for OF-10; OF-9; OF-8 & OF-7 are completely different for Navy and Army Dress Uniforms - Most similar at first glance are those for OF-10 all the rest are very different the Naval ones being much more elaborate.
OF-10 Admiral of the Fleet: The Crown is clearly above the Wreath with crossed Batons and the tips of the wreath are almost closed. These emblems also appear "inboard" i.e. at the neck end of the shoulderboard
OF-10 Field Marshall: The Crown is positioned in between the open tips of the Wreath with the crossed Batons and the emblems are located at the jacket sleeve end of the shoulderboard.