You could run into headspace problems installing a new bolt. If the headspace is short, that is easily solved with a .243 chambering reamer. But if it is excess, the barrel would have to be set back and with a pre-64 model that could create some problems with the stock bedding
Also, setting back the barrel would require timing of the sights and re-cutting of the breech cone and the extractor cut.
All do-able, but still a lot of work...
Hopefully his replacement bolt is close enough to the original bolt in headspace dimension.