Quote Originally Posted by Abasmajor View Post
Reference resources would date your Webley Mk3 to the transition period between Series 3 which ended around Ser No 25000 and Series 4 which went from there to around 39000. Production of the Series 4 started in 1957 and ended around 1961. These Series 4 air rifles are easily identified by the presence of the rounded stock rather than the more angular stock with the ribbed sides. So, your Mk 3 is probably an early Series 4 dating it to around 1957-1958.
Hope this helps
That is very helpful, thankyou. Another user has kindly offered to post pictures for me so you may be able to confirm your opinion.