I have come into possession of a signed, numbered print with a certificate of authentication on the back, but am unable to decipher the artist's signature. Does the number stamped on the back of the print frame have anything to do with identifying the print and or artist?

I have two Lithograph with the verification of authentication.The number is 375 on both.And there are numbers on left bottom.3+/3+5 and the other is2+/3+5.I cannot make out the signature on either picture.The picture has buildings with green shutters and there is a café called LE CARILLON Restaurant Café.BAR and on the awning it says AU CARILLON DE MONTMARTRE.It looks like the painter last name starts with Lyn not sure.Can you please give me any info on this.

I have an original lithograph of Nouvelle Gravure Internationale of New York and Paris, number 205/375 and I do not understand the artist signature. I believe it reads Louradow or Lousadon. Please can anybody help me identify the artist signature?
http://img291.imageshack.us/img291/303/sam0155s.jpg