Actually rebarrelling an 03A3 is nearly the same as for the older Win Model 70. The Spfld has a cutout for the extractor and a coned breach like the M70.
Mausers use a flat barrel face w/o extractor cut making them easier/cheaper to rebarrel. Spfld also has a different type of barrel thread. I've rebarrelled a couple using brand new replacement barrels that only required an action wrench and barrel vise. When tightened fully to place the extractor cut in the proper spot, the headspace was perfect. The replacements were setup to be installed in the field by unit armorers w/o need for a lathe or other tooling.