While I have nothing to add regarding the referenced K98, in the book The P38 Pistol Spreewerk Production by Jan Balcar and Ron Clarin, they have documented the "u" stamp being used on Spreewerk (cyq code) production in the Zero series with the "u" replacing the waffenamt markings. Most likely this was in the 1945 time range, but that is not for certain. Is it possible the "u" marks on these K98's has a similar function?
In addition, in the new expanded second edition of FN Browning Pistols, Side-arms that Shaped World History by Anthony Vanderlinden he states that the "MI" marking was not unique to FN. I would add, however, that if the part so marked is accompanied by the Waffenamt 140 or Eagle 140 then it would be FN production.
In addition, in the new expanded second edition of FN Browning Pistols, Side-arms that Shaped World History by Anthony Vanderlinden he states that the "MI" marking was not unique to FN. I would add, however, that if the part so marked is accompanied by the Waffenamt 140 or Eagle 140 then it would be FN production.