(a) The numerical sufficiency of any petition submitted pursuant to this part shall be based upon a number determined by the local Bureau official:
(1) By consultation with the tribal governing body regarding the current number of tribal voters; or
(2) For reorganized tribes, the number of members considered eligible to register for a Secretarial election and who are at least 18 years of age.
(b) The number shall be made available to the spokesman for the petitioners upon request along with a cut-off date when, for purposes of the petition, no further names will be added.