On one side it says "World Champion 1937"*, on the other side it says "9 Times French Champion". I have not yet found anything more about this; don't know if it concerns Road, Track, Cyclo-cross, Male, Female, Junior, Amateur or Professional.
The signature on the part at the top I have found out - Gérard Leroy - eventual owner (the son?) after the founder. Here he is behind the counter.
Frames hanging up, tyres and tubs hanging up, and bike parts in glass cabinets
I'm still struggling to find out what the signature on the bottom part says.
* I'm fairly sure it is 1937, but it could be 1931 - the French typically put a strike through on the sevens at least in written form.
EDIT: A correction after checking the signature much closely.
Yes I make that 37
Just lifted this from the shops Facebook...
Much later but interestingly frame and guards same colour..!? Maybe that's a shop thing?
Again proudly displaying the champion stripes!
@Mickeyspinn did some top detective work last night and sent me some great information concerning the 1937 World Championships and that signature name at the bottom of the seat-tube decal.
I've looked for photographs and can't find any of the event. Also, it looks like at that time the UCI were very picky about advertising and all bikes seem to have no decals at all - I guess they were strict that you were supposed to be riding for your country. Found this very cool advertising poster though that will look great in the man-cave with the bike.