Back to Demon's statement that there was a prohibition against selling .30-'06 rifles. There was no such prohibition and thousands of M1903 and M1917 rifles were sold to NRA members through the old DCM program.
Receivers were scrapped when they became unserviceable and many were sold to entrepreneurs who built rifles from them. In the 1920's and 1930's M1903 "low number" receivers on rifles returned to depots for rebuild were deemed unserviceable and scrapped. That policy was changed as WWII neared and it was felt that the need for rifles was so great that the risk involved in using those receivers was justified. Note that there was not, and never had been, a general "recall" on single heat treat receivers. Many served through WWII with no problems reported.
After the war ended, and sales of M1903 rifles resumed, any one having an SHT receiver ("low number") could return it (just the receiver) to DCM for replacement with a DHT or nickel steel receiver.