David,

Seashells of Eastern Arabia will definitely work for Kuwait, as it
covers Iran, Kuwait, Saudi, the Emirates, and Oman.  I think the book
you're referring to about Muscat and Oman is an earlier book by Dr.
Bosch.  Seashells of Eastern Arabia includes everything in the Oman book
plus much more.  It even has some micros in it.  I don't know how good
it will be for Kerala, as once you get outside the Persian Gulf the
number of shell species grows immensely.

Please let me know what you found in Kuwait.

Don Lycette