OP - pay attention to a part of earlier comment - you could pay to have that bolt face opened up for 7 mm Rem Mag; then pay to have the extractor attended to. And still end up with excessive head space. You did not reply if you have a way to check that - might end up having to again pay to have that barrel set back a bit. Of the rifles through here, probably 25% will fail headspace check when inserting another bolt - they "fit" into the rifle and bolt handle will close, but headspace is wrong - pretty much need headspace gauges to check that, although there are a few other ways to "check" that might satisfy you before the thing is fired the first time. Is also probable / possible that you can find a Mauser bolt for a Parker Hale from a belted magnum - faces will likely be all the same - 264 Win Mag, 7 mm Rem Mag, 308 Norma Mag, 300 Win Mag, 338 Win Mag and many others based on 375 H&H case head - but still have that headspace issue - if you notice, PH had a serial number on the rifle receiver, then same serial number on root of the bolt handle.
The stocks on the rifles might be different - that replacement bolt might require the bolt handle inlet in the stock to be deepened - you want the bolt to hit the metal stop - not to hit the wood stock - I just do not remember if Parker Hales were all the same or were different ones - goes to the shape and curve of the bolt handle.
