Kashi House description:

By the close of second Anglo-Sikh War (1848-49), the British had taken possession of 253 Sikh guns, of which 173 were either captured in the field or surrendered, and a further 80 found at forts in Lahore and Amritsar.

Published in: 'Warrior Saints: Four Centuries of Sikh Military History' (Vol. 1, page 174)

Images of this photograph can also be found at: [1]; [2]

Description of John McCosh's photography work in the Punjab and with Sikhs (from: [3], with grammatical improvements by me [the uploader]):

Though history of professional photography in India starts in the early 1860's when the British government invited photographers to take part in the Survey of India, there are many photographs that were taken earlier by different British military officers during the 1840's and 1850's. John McCosh, one of the first photographers known to have worked in India, was an army surgeon with the East India Company. He was based in Lahore and Ludhiana, just before the started of the Second Anglo-Sikh War, in 1847, and produced many photographs using the calotype process, including the only known picture of Duleep Singh as a Maharaja. The reign of this boy king, the son of Sardar Ranjit Singh, was ended by the war.

The McCosh's surviving photographs include over a dozen photos of Sikhs, mainly officers in the Sikh army, as well as some of the non-Sikh officers, who were also encouraged to grow long-beards. As well as photographing people, McCosh also photographed the Sikh palaces and other buildings, as well as landscapes and military scenes. A collection of military photographs attributed to him is in the National Army Museum, Royal Hospital Road, Chelsea, London.

Further description (taken from: [4]):

The McCosh collection in the National Army Museum in London, England, consists of 310 surviving photographs of British officers and their families. His portfolio also includes ten images of Punjabi subjects: apart from Duleep Singh, some Sikh Chieftains, granthis, and the samadhi (incorrectly listed as a tomb) of Maharaja Ranjit Singh.

This photograph may have originally been arranged on a page grouped together with other photographs labelled "Sikhs", with each having an album/mount caption, as per Elizabeth Edwards and Ella Ravilious in 'What Photographs Do: The Making and Remaking of Museum Cultures' (pages 142–143, 21 November 2022, ISBN: 9781800082984), available for free download via: [5]

Quote from the above discussing this:

A particularly notable discovery was a group of calotypes of Burmese architecture and people. Some were beautifully composed, but in general there was a sense of amateur experimentation about them. One of them was mounted on white paper with the handwritten title ‘Great Pagoda Prome (very ancient)’; however, of much greater interest to me was the reverse of the page. Here were nine empty spaces with torn sepia remnants where whole photographs had once been; each of the spaces was marked with an accession number, and the group was titled ‘Sikhs’, with the central image ‘Maharajah’. This was probably the result of a misguided attempt to lift the images from the page and potentially rearrange them according to new evaluations such as separating architecture from people, but I recognised this as a significant loss. Cultural knowledge enabled their identification as the earliest photographs of the Sikh people and their ruler Duleep Singh. The acquisition registers revealed that Dr McCosh deposited them in the Art Library in 1884, and subsequent research identified them as extremely rare prints by Dr John McCosh (figure 8.3).