The invaluable 150-year-old hand-written book, 'Bir Mrigesh', authored by unsung, historian pandit Sher Singh, primary source of information of the rise and fall of 'Sikh Raj' is missing from Bir Singh gurdwara at Naurangabad village. This is the largest book volume (runs into more than 2000 pages), ever written in 'Gurmukhi' script. The book has been replaced with a printed version (it runs into 1916 pages), brought out by Sant Jagjit Singh Harkhowalwale.

The annotated book, which has not been quoted by any historian, so, far, still remains the great primary source of Sikh history. The book unfolds vividly the working and the interplay of the forces which led to the fall of the 'Sikh Raj'. It also helps in determining the extent of the mischief of the forces which played false after the death of Maharaja Ranjit Singh. Those forces undermined the Sikh Raj which had come into being after much efforts. The book also contains the first-hand record of intrigues, conspiracies, plots stabbings and murders that followed the death of Maharaja Ranjit Singh. It also deals with birth of Sikh Raj in Punjab under Maharaja Ranjit Singh, the book also deals with conflict with the British and the downfall of the 'Sikh Raj'.

Dr Sheharyar a noted Punjabi writer said that the 'disappearance' of the hand-written book ever written in 'gurmukhi' script and 'Brij language was a matter of great concern. When he learnt that the hand-written book 'Bir Mrigesh' is missing from the Gurdwara which is under the SGPC he visited a number of villages to trace it but in vain.