The hub looks like a pre '55 A/B series and gold star up to '62
The part no should be 67-6136, the part no on the hub does not look like a BSA number. The A50/65 B44 type 68-6114 is identical apart for a thread to screw on the speedo drive dog
The later hubs 68-6114 do not have the grease nipple - the hub above is one of the earlier types of which I think there is a difference between Plunger and S/A types. See:-
http://www.britbike.com/ubb/bin/ultimatebb.cgi?ubb=next_topic;f=10;t=007221;go=older for some info
As Vic says, the A65 series hubs also have raised rivets, as the earlier ones are countersunk into the hub, they were known for pulling/working loose.