The Kokura, series 22 should have a chrome lined bore. The series 22 was made from Oct. '42 to June '43. Is the bolt matching? (last three of the receiver on the bolt root. By the way, the front sight guard was high for the first part of the series, then changed to the lower guard late in the 22 series. (this will make a difference whether you can remove the front band or not.)
The pictures don't show much of the stock. If it hasn't been sanded and still has the original finish, leave it that way.
Dean (the other one)
OFC-Orange Co. Ca Chapter