IR/840 Scottish Celtic unusual vintage silver sword brooch cheap hallmarked 1965

An unusual Scottish Celtic vintage silver sword and shield brooch but it's not a shield it's a circle with 2 thistle heads and leaves, you don't see this form very often, it's a good well made brooch by Robert Allison and hallmarked in Edinburgh in 1965, the hallmark is a bit worn but is easily identifiable as stated, also stamped "Scotland" to the rear of the crossguard, 8 cm long which is around 3 inches, longer than the average brooch of this style and 2.5 cm or about an inch across the circle, good pin and good "C" catch, it has been recently cheap cleaned, professionally which is obvious by the finish.