The pattern appears to be based loosely on The King's Pattern but it is much more embellished than that.

 I have spent hours looking for a match, I even asked a London Silver dealer for help, he had catalogues going back to 1908 

and couldn't ID it but thought it may well be late 19th century and could be a bespoke design.

  Any input would be appreciated. 

They came in a 4 tier M&W brass bound oak campaign chest style canteen, so were incredibly expensive when new.

On the front, in the cartouche is a charming "AEH" monogram, the tip are all perfect, there are no defects.

On the rear, they are stamped;

 MAPPIN & WEBB,

 PRINCE'S PLATE, 

 Then a gothic "U" date letter. As we know the workings of the M&W dating system is an alchemy known to very few but they are pre 1908.

 The rear cartouche is vacant. An attractive shell design to the back of the spoon .

They are 7.5'', 19cm, long and weigh 73g.

 All near perfect, straight as a die, and the plate is unrubbed.

 Part of a Mappin & Webb collection and of plated and silver table wares, please see other listings.  Discount for multiple purchases.

 There are three other listings with this patterned cutlery.

 Will post Worldwide, price dependent on destination.