The original saroop of Sri Guru Granth Sahib Ji written by Bhai Gurdas Ji was shown by the Sodhi family in Kartarpur, Punjab. Sri Guru Arjan Dev Ji brought this saroop inside Sri Darbar Sahib for the first parkash.
Dhir Mal stole this saroop and now it belongs to the descendants. Guru Gobind Singh Sahib Ji let Dhir Mal keep the saroop and Guru Sahib had Bhai Mani Singh Ji write while Guru Sahib recited entire Sri Guru Granth Sahib Ji.
This saroop is only revealed at Kartarpur near Jalandhar on the day of Vaisakhi for the last hundreds of years.
Brief history on the Bir:
Both tradition and historical texts agree that the the Adi Granth was shifted from Amritsar to Kartarpur when the family of the Sixth Guru took up residence in that city. It is accepted that the original Adi Granth remained with the family of Dhir Mall, the great grandson of the Guru, and his descendants at Kartarpur, even after the Gurus had shifted from there. It has remained in the custody of the Sodhis of Kartarpur. After Maharaja Ranjit Singh came to power, he procured the Granth for himself and kept it with him as a national treasure of the Sikhs.
After the British conquest of the Punjab, the Bir passed into the hands of the Indian Government. Thereafter, the Bir became the subject of a civil suit and it was restored to the descendants of Dhir Mall.
So after leaving Amritsar, its custody was first with the Sodhis of Kartarpur, then with Ranjit Singh, and again with the Kartarpur family, this is an important piece of evidence. Because, the presence and recovery of a manuscript, document, or book from its natural and proper custody and environment is a relevant and weighty factor in showing its originality.