Hi Hannah
Here is the link to the baptismal records in Calcutta. It seems to be a one off collection which have been both transcribed and the original digitalized. Unfortunately it only has records dating from 1778-1782. It would be fantastic if further records came to light in the near future.
http://myweb.tiscali.co.uk/cmadge/Baptisms%20in%20Calcutta%201778-1782.pdfThe Francis Latour memtioned in these records is recorded as being a Matross. Matross was a soldier of artillery, who ranked next below a gunner. The duty of a matross was to assist the gunners in loading, firing and sponging the guns. It would seem that this Francis Latour is not the same as JFL in Madras, and there is certainly no mention of a daughter Mary in his Will.
Again as Dawn mentions I have found the records on FindMyPast invaluable for moving my research along and I have been able to establish and confirm so many more family links by using this site.
Good luck with your research. Please feel free to share any discoveries here.
Regards Perks1