Originally Posted by T-Mar

The logo style is newer and the cage style on the Honor (?) rear derailleur was introduced for 1976. I believe it to be a 1977-1978 model manufactured in 1977. If not for the space between the 5th and 6th characters, the serial number format would match Bridgestone and those crimped and spot welded stays are typical of lower end, contract manufactured, Bridgestone product.