Kingsdown Antiques has dated this piece to the 1910s.
They are also marked A1 which is for first class quality silver plate.

The set was almost certainly made exclusively for Harrods London. In over 40 years of dealing in antiques this is the first set I have ever come across.
Measurements:
Serving Fork Length: 6 1/4" (approx. 16cm)

Serving Scoop Length: 6 1/4" (approx. 16cm)
Fork Length: 5 1/2" (approx. 14cm)
Knife Length: 5 3/4" (approx. 14.5cm)
Total weight: 345g
In good condition - any dark areas are shadows from the photography.
Kingsdown Antiques has dated this piece to the 1910s.
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