D4 generally indicates Damascus Grade 4 and the C could also indicate a Grade 4.
With a 3 lb., 4 oz. barrel weight it seems to be a sixteen gauge 0-frame or a 20 ga.
"Fluid Steel" and D4 don't go together and I have never seen Parker barrels marked "Fluid Steel".
Nothing you have listed are Remington codes.
Can you post some pictures?
|