The Manton firm exists on paper, as does Rodda. Some of the other companies in Calcutta / Kolkata including Daw, Biswas and Lyon and Lyon also exist on paper though none of them sells guns as far as I am aware. None of them has done much business since 1984 when the import of guns into India was banned. I did try talking to them about copies of their records for a British website some years ago but their terms were ridiculous.

Delhi has other shops but none of the old names as far as I am aware. And the Indians For Guns website is a joke. I used to post there but haven't been there in several years. Unless you want to waste time, there's no reason to bother with checking there.