When a pronoun is subject of a gerund-participial clause, it can be either accusative or genitive:
(1) Us/Our telling you about the paper is no use. [clause is subject of main verb 'is'; 'us' or 'our' is subject of verb 'telling']
(2) They objected to us/our telling you about the paper. [clause is complement of preposition 'to']
People might have different preferences about whether to use 'us' or 'our', but both are very common in standard English.
In your original sentence, the subject of (1) has been displaced to the end, and a dummy 'it' has been added as new subject. You could do the same thing with 'our':
(3) But it is no use our telling you about the paper. [clause is displaced subject]