While it is true that the land has been allotted by the government for industrial purposes and as such, this land and building constructed upon it and/or part of it cannot be alienated. Hence it is true that you cannot claim a share of the business or the assets of the business which includes the property and or lands as above mentioned
But that does not mean that your dues should be limited to the accounts for the year ending 2004. According to the Hon'ble Supreme Court : " If a partner dies, the surviving partners may crry on the business by forming another partnership. In such a case, they will have to account for the share of the Deceased partner to his legal representatives. But if a partner dies, his legal representatives may be admitted to the new partnership by the surviving partners"
The legal representatives in my opinion should also include legal heirs in death.
Also Scetion 37 of the Indian partnership Act further states :
Where any member of a firm has died or otherwise ceased to be a partner, and the surviving or continuing partners carry on the business of the firm with the property of the firm without any final settlement of accounts as between them and the outgoing partner or his estate, then, in the absence of a contract to the contrary, the outgoing partner or his estate is entitled at the option of himself or his representatives to such share of the profits made since he ceased to be a partner as may be attributable to the use of his share of the property of the firm or to interest at the rate of six per cent. per annum on the amount of his share in the property of the firm: Provided that whereby contract between the partners an option is given to surviving or continuing partners to purchase the interest of a deceased or outgoing partner, and that option is duly exercised, the estate of the deceased partner, or the outgoing partner or his estate, as the case may be, is not entitled to any further or other share of profits; but if any partner assuming to act in exercise of the option does not in all material respects comply with the terms thereof, he is liable to account under the foregoing provisions of this section.
You may first serve a notice upon your uncles as well as the Partnership firm at its registered office either claiming th estate of his share for which you must know what was his share iin the Partnership Agreement or also seek a settlement of dues. For better appreciation you must consult a commercial lawyer with all documents.