I hope this is the right forum so apologies to all if it is not. My low 46xxx numbered stock on my Inland highwood stock has the Trimble and TN stamp but in the middle of the oiler well is impressed the flaming bomb. No flaming bomb on the barrel although dated 9-42. Is this an unusual marking? This carbine was a duffel bag bring back by my now deceased acquaintance who was a non front line and was issued this carbine. I do know he carried this carbine inverted and this is easily recognizable by the wearing of the front snap into the top and bottom wood making a slight but obvious groove. I never did learn his specific duties, guess I should have asked.
In all of my material I find no mention of Inland having used Trimble made stocks. I also checked to see if any were shipped from another carbine maker which did happen but the earliest I can find was from NPM who did use Trimble stocks but it was in July 1943 which would have been too late for your serial number. Many early stocks were stamped with the ordnance bomb but that was dropped during production. An Inland high wood I cut stock for your serial number would be one stamped OI with or without the bomb stamp. The stock could have been changed while he was in a cleaning party and the wrong stock was picked up or his was damaged and replaced. No way to know for sure now but I think you should enjoy it just as it is as I am sure it's very special to you.