I'm not convinced, wether the clasps are the same. The clasp from France looks IMO smaller than the one from Prince Michael's christiening. Here again both pictures...
Picture in Beth' post from September 3, 2015 - 2.14 (Unveiling Australian National Memorial in Villiers Bretonneux, Somme/France, July 1938)
Picture in Beth' recent post - the clasp/brooch looks much bigger than the one in the picture above (which is even taken from a less distant point) (Prince Michael's christening, August 1942)