I stubled across a Mauser that someone had started to turn into a 223 and quit. I decided to finish it ( into a 17 Fireball ) and am close to done except extending the extractor for the smaller case
Brownells used to carry a blank extractor and I have been watching but that seems to be a thing of the past.
I have a gas setup and could probably weld it with some care but it seems a TIG would be the best option.
With some care the spring temper could be saved