Webley Typhoon Air Pistol

The W’s are contemplating upgrading their air rifles, and in thinking of trading in some of our old guns we remembered Pauline’s Dad’s old air pistol still in its box.
 
We have no intention of trading it in, but what it’s current value is did cross our minds.  To cut a long story short, the only Typhoons of this era I could find were ‘SOLD!’ with a vengeance and no idea given of the price/value.  I can only guess it may be worth a bob or two in it’s box.
 
Not withstanding any pending fortune this evening this little pistol may well see some action for the first time in thirty or forty years.