As far as sporting model 'pre '64' Win 70 genre, it would be 'possible' for a special order gun to have been shipped without checkering. That especially if a 'pre-war' gun when the factory was more 'into' such caterings. That said... Unless some kind of provenance speaking directly to such "order", Occam's Razor firmly decreeing: "aftermarket alteration"!
The "collector value" largely gone. The 'residual value' yet possibly substantial particularly if one of the rare factory barrel variations.
A 'quality shooter' in most any case if properly maintained and otherwise "Bubba's" presumed hand, limited to a decent refinish!
Just my take
Best!
John
