Last summer my husband found this Motobecane frame (only the frame no other parts) in a thrift store and he built me a bike. The "Motobecane" on the frame is in script lettering and not the typical block lettering I've seen on every other bike. It has the original badging and the sticker of the original store in Seattle that sold the bike and the serial number is 1819069. Any help with the year would be appreciated and I believe it is the Mirage model????