I got really lucky to find this tin sign today, it's a lithographed tin sign made for the automobile club liegeois here in Belgium, it was made around 1920 by Prager & lojda - Berlin SW
the sign is heavily embossed with curious lithography, it's not damaged at all on the bottom, it's grey cloud, it's in the original paint and not a defect, every sign I've seen from this one are the same : http://www.bonhams.com/auctions/19291/lot/109/
Now I have to find a place on my wall for this beauty