A substantial part of Punjab's documentary record is outside both Punjabs.
The British Library's India Office Records hold the correspondence of the Punjab administration, the Residency at Lahore, the annexation, the settlement reports, the military records and the intelligence files on the Ghadar movement and the Akali morchas.
The National Archives at Kew hold the Punjab Boundary Force papers, the 1947 political correspondence, and much else.
United States and Canadian archives hold the Ghadar Party records, immigration files, and the papers of the early Punjabi communities on the west coast.
Almost all of it is now catalogued and much is digitised, and any of it can be consulted by a researcher who can get to London or who can pay for copies.
That is a real advantage and it is not used. Punjabi researchers working on their own districts often do not know that the settlement report, the census village directory and the district correspondence for their village exist and are free.
The Bodleian, the School of Oriental and African Studies and a number of regimental museums hold Punjab material as well, including private papers of officers and administrators that were never deposited with any state.
Reader registration at most of these is free and the catalogues are searchable from anywhere. The barrier for somebody working in Punjab is the fare and the visa rather than the permission.
All of it is catalogued and much of it is digitised, which makes it more accessible from Punjab than the material held in Punjab is.