Pup (Total: 1,954, Canadian: 18, Group 0)
Sopwith Pup

The Sopwith Pup quickly became a favourite with pilots of the Royal Naval Air Service (RNAS). It was superior to the Fokker D.III and more than a match for any of the new Halberstadt and Albatros scouts.
Armed with a single synchronous machine gun, it was lighter and less dangerous than its successor, the Sopwith Camel. Although underpowered, pilots liked the plane because it was maneuverable and fast. It could climb and hold its altitude better than any other fighter. In August 1917, the Sopwith Pup was the first aircraft to land aboard a moving ship, the Royal Navy's H.M.S. Furious. Canadian crews saw service with Sopwith Pups while attached to the Royal Naval Air Service.
At least three Sopwith Pups were also allocated to No. 1 (Fighter) Squadron of the Canadian Air Force (CAF) at Shoreham-by-the-Sea in the UK in 1918 likely as proficiency trainers. No. 1 (CAF) Squadron had Sopwith Dolphin and Royal Aircraft Factory S.E.5a's on strength as the primary fighter aircraft. Kestrel Publications
I have looked up the booklet that is all I have on the Sopwith Pup. There is a brief list of the serial numbers, And all I can tell is that B5333 and B5348 were built at Whitehead Aircraft, Richmond as part of the series B5251-B5400. None of the serials B4158, B4148, B4338 that you asked about seem to be valid according to the list that I have here (no serials from any of the producing factories begin with B4).
Pup serial A7321
s/n A7321
A 7321
Known Units:
last update: 2025-June-01
Pup serial B3898
s/n B3898
B 3898
Known Units:
last update: 2025-June-01
Pup serial B4158
s/n B4158
B 4158
Known Units:
Operated by No. 1 Squadron, CAF, at Shoreham-by-Sea, c.1919.last update: 2025-February-05
Pup serial B4159
s/n B4159
B 4159
Known Units:
last update: 2025-June-01
Pup serial B4338
s/n B4338
B 4338
Known Units:
Operated by No. 1 Squadron, CAF, at Shoreham-by-Sea, c.1919.last update: 2025-February-05
Pup serial B5333
s/n B5333
B 5333
Known Units:
Operated by No. 1 Squadron, CAF, at Shoreham-by-Sea, c.1919.last update: 2025-February-05
Pup serial B5360
s/n B5360
B 5360
Pup serial B5399
s/n B5399
B 5399
Known Units:
last update: 2025-June-01
Pup serial B5972
s/n B5972
B 5972
Known Units:
last update: 2025-June-01
Pup serial B7530
s/n B7530
B 7530
Known Units:
last update: 2025-June-01
Pup serial B8012
s/n B8012
B 8012
Known Units:
last update: 2025-June-01
Pup serial D3399
s/n D3399
D 3399
Known Units:
last update: 2025-June-01
Pup serial N5192
s/n N5192
N 5192
Known Units:
last update: 2025-June-01
Pup serial N5193
s/n N5193
N 5193
Known Units:
last update: 2025-June-01
Pup serial N5194
s/n N5194
N 5194
Known Units:
last update: 2025-June-01
Pup serial N6170
s/n N6170
N 6170
Known Units:
last update: 2025-June-01
Pup serial N6181
s/n N6181
N 6181
Known Units:
last update: 2025-June-01
Pup serial N6440
s/n N6440
N 6440
Known Units:
last update: 2025-June-01