During the German occupation, when BHP serial numbers reached 200000, the Germans decided to roll back to 1 and use suffix letters. Number 63000b was reached before the liberation.
That pistol probably has the full serial number on the slide with only the last three on the frame.
There were three German officers assigned inspection duty at FN. The officer assigned number 613 was first, from 1940 to early 1941. The officer using 103 was on duty from early 1941 to late 1941. The German officer assigned WaA number 140 was at FN from late 1941 to the liberation in 1944.