This is a CWD locomotive, but the location and date of this photograph are uncertain. From the truncated road number and decoration style, it is possible this is a Pakistan Railways CWD locomotive, from the 1950s or later. It is also possible it is an A/CWD locomotive somewhere in India.
The scan was obtained from WR archives with a caption that suggested this is the locomotive hauling the first BB&CI Railway train at Grant Road station in 1864, but that is definitely incorrect as this is a CWD class locomotive that was manufactured only in the 1940s.
Courtesy of Western Railway archives; scan provided by Rajendra Aklekar.