What numbers are you looking for, Serial numbers? Patent numbers? Serial numbers were not required when that rifle was built, while some large manufactures used serial numbers as a method of production control, many of the other smaller makers ( At that time, later Stevens became much larger ) did not bother taking the extra step involved in stamping serial numbers, their production was not large enough that they needed serial numbers to keep track. Any patent numbers were probably removed when the gun was modified. The , whatever you want to call it, was probably made in the 1930's. And yes, it is a no no to make a pistol out of a rifle unless you have prior approval and have purchased a tax stamp. You can't get approval after the fact.