Yes, the ancestral property after partition shall be treated as self acquired.
Now daughters too have equal share in HUF property and can also become karta of HUF if eldest.
Your grandfather can will/transfer his share in property to his daughter.
The Hon'ble Supreme Court of India held that the plea of oral partition can be accepted in exceptional cases where it is supported by the public documents. If you wish to take my legal opinion professionally , then can whatsapp at 9830019661 or can EMAIL firstname.lastname@example.org .....Sinjari Bandyopadhyaya, Advocate of Calcutta High Court