Translations for customer in French

Here are paragraphs from public domain books translated:

“Takes your breath away, chief, doesn't it? So it did mine, on the day when you came to see me here and when the notion was beginning to grow upon me. I was flabbergasted with astonishment. And yet I've had experience of my customer. I know what he's capable of.... But this, no, this was really a bit too stiff!”	« Ça vous suffoque, n’est-ce pas, chef ? C’est comme moi le jour où vous êtes venu me voir ici et que l’idée me travaillait. J’étais abruti de surprise. Et pourtant, je l’ai pratiqué, le client. Je sais de quoi il est capable… Mais celle-là, non, elle est trop roide !
The Confessions of Arsene Lupin, by Maurice Leblanc	Les Confidences d’Arsène Lupin, de Maurice Leblanc