Version 4.2.4 (Classic)

Translation for Tailoring should be:

in Guildbook_Locales.lua line 418 for tailoring:
L['Tailoring'] = "Couture"

in Guildbook_Locales.lua line 419 for Leatherworking: (Typo in the Key => Leatheroworking)
L['Leatherworking'] = "Travail du cuir"

in Guildbook_Locales.lua line 417 for Jewelcrafting: (in preparation for TBC)
--L['Jewelcrafting'] = 'Joaillerie',

I made you a pull request for the Locales:
#10

Hi many thanks for the info I will update this evening.
Are the other bits ok?

The rest looks ok but I don't have all the professions :)

EDIT: Skinning is wrong, fix with:
L['Skinning'] = "Dépeçage"

I think the new locales table Guildbook.ProfessionNames should also contains:

[129] = "First Aid", -- (for enUS)
[129] = "Secourisme", --(for frFR)

Not sure about other language ;)