A vintage shirt, probably made in the 1970s or thereabouts.
Billings and Edmonds.
Judging by the style and size - and the fact that Billings and Edmonds are school uniform specialists - I think it was probably a large school shirt (for an older boy, perhaps a teenager), rather than a small man's shirt.
As the cuffs have cufflink slots rather than buttons, it was presumably for a public school rather than a state school.
The label is marked:
BILLINGS & EDMONDS LTD
24 DERING STREET, LONDON W.1.
and also with the Royal Warrant - BY APPOINTMENT TO H.M. THE QUEEN, TAILORS AND OUTFITTERS.
Single cuffs for cufflinks.
The material is Viloft (Courtaulds Viscose/Polyester mixture).
Size (from garment measurements)
Collar size: 15 1/2 inches
Chest measurement, armpit to armpit: 44 inches
Length, neck to hem at the back: 29 inches
Length of sleeve, shoulder to end of cuff: 23 inches
Length of sleeve, armpit to cuff: 20 1/2 inches
Shoulder to shoulder: 17 1/2 inches
Weight 220g approx.