As usual with Mercury, the carb is NLA and so are many of the carb components (jets, screws, float, ect) so don't drop or break anything or the whole motor will be scrap.
They don't offer a "kit" but a bowl gasket and needle valve can still be bought (quite expensive).
http://www.marineengine.com/parts/mercury-outboard-parts/35/64223740-and-below-m/carburetor