No, the OI stands for "Overton for Inland". Most carbine stocks and handguards were made by the Overton company (O) as a subcontractor; the second letter would be the prime contractor. (The other major supplier of wood for carbines was a company named Hillerich & Bradsby, of which you might have heard in connection with other, less serious, contests.)
The markings on the stock I was referring to were the Ordnance symbol, inspection cartouche and the stock maker's marking on the grip. Those absences indicate that stock was not installed at the factory, but in the field. It could have been a replacement, or installed because of a need for paratrooper carbines at a particular time. Or as a replacement by an owner after the war to make the carbine look "sexy".
Jim
The markings on the stock I was referring to were the Ordnance symbol, inspection cartouche and the stock maker's marking on the grip. Those absences indicate that stock was not installed at the factory, but in the field. It could have been a replacement, or installed because of a need for paratrooper carbines at a particular time. Or as a replacement by an owner after the war to make the carbine look "sexy".
Jim