Some or one of the old importer ad's refereed to a No6. Apparently the gun posted by dan was inspiration for using that name. I dont know if the OP gun was fabricated and sold as a No6, but some definitely were, Instead of a poor copy of the No5, this now becomes a clone of the No6. Good post!

I also missed that this was a 308. That maybe a handful for casual shooting. I would want to reload for that, if fun shooting at a club was on the agenda.