G'day Huvius, a few of these are owned by mates of mine. The first has a serial No with an " A " prefix and is believed to be retailed by Purdey. The next has a serial No with a " B " prefix and is believed to be retailed by Gibbs. It is a take down and exhibits a lot more file work than yours. A third has marks on it which has lead us to believe it went through the hands of Rigby. I think you're on the right track in regard to where yours came from and they all handle wonderfully.