Bulova 1957 Senator

I believe this is a 1957 Senator B on its original band.  Attached a couple of partial adds from 1955 and 1956 which seem to match it.  Yellow RGP case measuring about 27.5 mm x 28.8mm not including the lugs and crown.  Clean dial with sunken seconds at 6 position.  11AC movement that is clean and running well.  L7 movement and case codes.  Has a Bretton branded band that looks great and appears to match those shown in the two partial adds I attached.  

Thanks for looking!