I've actually found a great online resource for records from Martinique. Take a look at http://www.patrimoines-martinique.org/
to see if they have anything you might be looking for. I made one of my most exciting finds there, so I hope it can do the same for you.
I found my ancestors in records called actes d'individualite, which were issued a little after timeframe your interested in, in 1848 and 1849. While this was exciting I wasn't sure what the records really meant, so I had to do some research. You can take a look at my genealogy blog entry for a summary of what I pieced together: http://iamthediaspora.wordpress.com/2011/07/12/actes-dindivi...
The website has other records that I am less familiar with, so there are more possibilities for you to explore there besides the actes d'individualite. Good luck!
I'm interested to hear what other suggestions people may have for researching Martinique.