I am very certain what you have is a FN Deluxe rifle. I recently bought one of these in 270 Winchester.
A picture of a vintage ad is here:
http://store.valueweb.com/servlet/vintagepaperads/-strse-52365/1954-F.I.-Gun-Ad/Detail
I have limited documentation, but I believe these were post war, made up to 1956 or 1957, imported by FIE. These were not cheap rifles in their day, you could buy a M70 for $109 or a FN for $148 with sights. With inflation $140 is $1200-1300 in terms of today's money.
These early FN's share more M98 features than the later FN Supreme. The 98 action is the best overall action ever built. Later actions were cheapened to compete with lesser rifles on the market. These older actions have more safety features and better machining than the later actions. That military bolt shroud uses a safety that cams back and positively blocks the forward movement of the firing pin. To get that firing pin to go forward you have to shear the shroud safety or break the firing pin. Later actions used a sear blocking safety in the trigger mechanism which is not as positive or as certain. Sear blocking safeties have been known to "jar off".
I took pictures of my bolt and you can see some of the safety features that Paul Mauser designed into this action.
The firing pin has an interlock. If the firing pin breaks and the lugs are not engaged, the firing pin cannot reach the primer. You can see the interlock through the gas ports. This feature was deleted in later FN actions and I am not aware of this feature in any American bolt action. All other actions the firing pin tip will stick out through the bolt face if the firing pin breaks.
The 03 Springfield has a very poor and weak firing pin design. I have had strikers, collars, and firing pin tips break in these actions. Thank god nothing evil happened to me. Jack O'Connor had a 03 which broke its firing pin. He did not know that the firing pin was sticking out, the next round went off before the bolt closed, and Jack almost lost a thumb when the bolt blew out of the rifle.
Interlock on, firing pin flange not in bolt recesses, firing pin tip inside bolt
Firing pin rotated, interlock off, firing pin flange in bolt recesses.
If there is gas escape from a pierced primer or a blown case head the firing pin will move backwards in all bolt actions. In the M98 action the firing pin moves backwards to this point and is stopped. This also effectively blocks gas from coming right down the firing pin shaft into your eye. It works as I have had pierced primers in military Mausers and never received gas in the eye. If you ever get a pierced primer in a M70, better be wearing glasses!
This feature was deleted in later FN actions.
You can see the guide rib on the bolt, deleted in later FN actions and you can see the third safety lug. This safety lug also blocked gas coming under the bolt, and it was removed in later FN actions.
Your rifle was drilled and tapped for a scope some time later in its life. . Based on these ads, the rifle came from the factory drilled and tapped only for receiver sights. I have never seen one of these receiver sights so I guess most of them went in the trash can. I do not know if a Lyman 48 M will fit these rifles.