I should think that we do not see enough of these to say much more than wow!
It seems to partially match an example reported by 'Alamas';
Latin-font "F338XX", 'type 3' upper band, "Greenish coating" on the Butt-stock. The carbine mentioned was parkerized on all steel parts, with a leather sling and beech fore-stocks. No mention of the stamped magazine plate, but that and a 1950s dated barrel would seem correct.
The post-War examples, such as this, are so rare that the military configuration, if only just one exists, has not been well defined. It would be helpful if those who know, would instruct those of us who do not.