Hi
That one is in my database. I saw it quite a while back on GB. I noted at the time that the stocks numbered to the gun, so they are original. I do not have an actual ship date for it, but it was a commercial shipment and very likely left the factory in March, 1946. Postwar civilian shipments started on the first of that month. By mid-April, no further shipments of these unit wore the prewar style stocks. Moreover, I have several serial numbers recorded in that range that shipped in March, 1946. I'd give very good odds on a bet yours shipped that month.
Nice p4th, 1948.
Incidentally, several guys here will tell you that it is not a "pre-Model 10." It still has the long action. The High Speed Hammer (which defines the so-called "pre-Model 10") was not introduced until March, 1948. The first production unit with that hammer was S990184, and it shipped on April 7, 1948.