Cub
I have a black one with a missing end cap and spring. All my references seem to indicate it was possibly just post war (1945 onwards) and is made from aluminium. (Hiller recons they were made from redundant Spitfires using kit taken from Nazi Germany a la Milbro Dianas).
As far as value, probably not much as most collectors do not pay much attention to pop-outs (I am a bit of an nerd for them) but should fetch £20 or so (possibly another fiver).
If you decide to sell I would be interested, as I say I am a nerd for pop-outs - I think I have one of each of all the variations of the Diana mod 2, pre war until discontinued.
lodmoor
Always ready to buy another Webley pistol and another and . . . .