Webley pistols before they used stirrup catches on barrels?

[RetroBloke]

Hi,
I've been helping a mate move his mum to a smaller house and we found an old Webley that most likely belonged to his dad years ago.
I thought I'd seen most variations of the typical Webley air pistols but this has no stirrup catch to hold the barrel, more of a sliding block by the rearsight.
It seems to be too large for a junior so I'm guessing it's a Mk1 or Senior.
I know some very early grips were ribbed but his are normal so I'm thinking "early" rather than "very early"

Sorry no pics. Mate will be keeping it but if anyone has any info or can identify it from the description I'd like to know just out of curiosity.

cheers,
Pete

[Troubledshooter]

If it has plain wood grips with a flying bullet insert on the left grip, it is an early pre war Mk.1, other than that, the later Mk.I had black Bakelite grips, with the pre war version not having 'Webley' on the top of the grips, and both models should have 'Mk,I' signified on the body.
All Seniors had stirrup catches.

[deejayuu]

Here's a Mkl