Following WWII the Belgians were short of rifles, their's having been taken by some passing German tourists.
So, they needed immediate rifles for use in the Belgian Congo and in Belgium.
They were developing the FN Model 1950 semi-auto, but as a fill in until it was ready they just produced '98 Mauser's on the tooling they'd been using for FN Mauser's bolt rifles since WWI.
After the war the US gave Belgium and many other countries vast amounts of US 30-06 ammo so it made sense for the Belgian's to chamber the Model 1950 Mauser in 30-06....... the only Mauser military rifle ever originally made in 30-06.
The receiver mark has the letters "ABL" standing for the three languages used in Belgium.
There were two versions of the rifle, one with an "L" for King Leopold, the other with a "B" for King Baudouin.
These are very desirable Mauser's for both the quality and caliber.
The versions used in the Congo are typically in badly used and pitted condition, the European versions are usually in much better condition due to the better conditions and limited time they were in service.
As above the stock has been refinished, the bolt handle bent, and the metal reblued with a gloss finish.