I am quite new to this 'posting' so apologies if this is in the wrong place!

I acquired a Webley Mk 3, serial number A2553 in 0.22 calibre which is in very good condition and shoots very well.
Reading various posts there appears to be a wide variance in dates and costs for a Mk 3.
As this is surplus to my requirements and am thinking of selling this after Christmas.
Can anyone kindly advise:

a. How old this rifle is?
b. What a fair price would be?

Many thanks for any help!
Graham