My observations on your Greener gun are as follows,
Guns marked F4 fall into Greener's third system of grading and are applicable to guns made in the period 1893-1903.Gun #48914 was made in 1900 which fits into the grading system time frame.
The F4 non- ejector is listed at price 35 gns;[=37.9 pounds] Most makers of the era charged 5 pounds extra for Whitworth Steel barrels. Likely your gun was a special order.
One concern that I have is that the slots in the action that accept the barrel lugs appear to have been peened over to stop side play in the barrels .This issue in should be reviewed by your gunsmith at the time the barrel dent is raised.
The triangle stamp on the gun barrel flats is an indicator of chamber length. A 12C in the triangle indicates a maximum 3 inch chamber. This Mark is usually seen on 2 1/2 chambered guns. If the mark in the triangle mark reads LC a chamber length exceeding 3 inches is present. Chamber length should be confirmed by your gunsmith.
Your gun is Black powder proof tested.[ not Nitro].
A nice early Greener.
