S stock without grasping grooves is correct for the 03A3 Rem. Post the serial number and pic's of the stock cartouches.
Get the correct bolt and do not cut on the wood! The correct bolt well be marked with a R, I may have a one or two I well sell cheap, plus all the internal parts.
The floor plate is stamped. The Rem FP is smooth all the way to the front screw, the Smith Corona FP was a semi-circle stamp mark just before the FP screw.
ETA: I want to correct a mis-statement on the Rem floor plate, it has a straight stamp mark at the front screw and the SC is a semi-circle.
This is a Smith Corona floor plate.