Looks to me like a bog standard Selmer Bass Clarinet from the 50s to the 70s, with a serial from the late 60s. It looks very much like the horn I borrowed from my high school for the four years I went there.
All of Selmer's basses in that period were the same design, regardless of if they're marked as a Series 9 or not. (Well, some went to low C or E, but they're still the same design bass, just with more or less keys downwards.)