No “force matching” there. That carbine is correct as they come, although the white fill was not standard. Your carbine began life as a magazine lee enfield carbine, Mk I*. Subsequently converted to the RIC pattern for constabulary use. You are correct:it has enfield rifling. Looks like the only missing thing is the brass screw which secures the stock disc. Prices vary on where you live, but $1200 to $1700 appears to be the auction norm. Ive seen lesser examples go for $950. You've got a beautiful one there, congratulations!
So the different suffix of A on the bolt vs B on the barrel and receiver is normal? The white should come off easy enough. I never add it to my Rifles but if someone else did first I usually leave it. Thank you for the info.