This is the only info IGC has on Hamilton:

Name Hamilton & Co
Address1 Unknown
Address2 Old Courthouse Street, Dalhousie Square
City/Town Calcutta
Country India
Trade Jewellers
Other Address Simla and Birmingham.
Dates 1860?-1947?
Notes

A .450 (3 1/4 inch) BP Express rifle profusely inlaid in gold and dated to 1899 has been seen. The locks were signed J Woodward.

Hamiltons were a large firm of jewellers but, obviously, did not confine themselves entirely to traditional jewellery. In the 1920s and 1930s the manager in Calcutta was a Mr Frank Read who was a close friend of F B Prike of R B Rodda & Co whose offices were in the next street.

I suspect, given the previous posts, that the J should have read T Woodward for the rifle above. KK also wrote 'Simia' when 'Simla' is more likely, it being an Indian town, now called Shimla, apparently.

Tim