hi the cocking lever has a button push and on the end of the butt there is a removable plate to give access for room i think for a cleaning kit
Hi, That sounds like a 1920's era gun then, the butt trap on these is a wooden oval cover secured by two small screws with a convex oval spring under it to help release, the purpose is to allow access to the stock retaining bolt, If you shine a light you will see a slotted head down the 'ole
Gun below is a 1919-39 era one (they did change a bit but this is showing all the general shapes of the bits etc.)
If it has a full size metal cover to the butt then it is an earlier stock, most parts interchange between eras so can get confusing when stuff is replaced
Also used for hiding messages, or putting weights in etc. etc., but not really designed to be taken on and off as can break if levered out without care.
ATB, Ed
If it has a letter prefix then it will be made after 1919 (Ok not 100% true since some pre WW1 rifles had the S prefix (these were the ill fated double sear models made between 1912 and 1914 I believe) but the L/C/CS/A/S (The ones without the double sear) ect are all post 1919.