During the war years, material was scarce and labor was cheap.
When I arrived at Durango in 1981, re-using tubes was a standard DRGW practice. In most cases, after removal, the ends were cut off the tubes (making them all the same length) and then scaled and cleaned. In most cases, short sections were cut from new tube stock to make "safe ends" to be welded to the end of the used tubes. In some cases, multiple used tubes would be welded together as reconditioned tubes. This was apparent from many of the tubes we pulled that were reconditioned by the DRGW in previous years. I spent many hours cutting and scaling tubes and preparing safe ends for welding.
MD Ramsey