SC, so it's not a magnum length action already? Many Safaris already were magnum Mausers - i had thought yours was already. Hmm... you might be in trouble then. Try contacting Bill Leapers and see if he can do it.
Problem is you have to lengthen the action at the back behind the mag box as far as it will go AND lengthen at the front inside the receiver ring and shorten the feed ramp. You also need to work on the feed rails a little for the wider cartrige base and open up the bolt face too.
ALOT of smiths feel that this leaves too little steel behind the lower locking lug at the front of the bolt. Such a conversion, IF you can get it done at all in Canada, will also probably necessitate re-heat treating the receiver.
At this point, if you're devoted to using your barrel, it will likely be a better idea to trya and trade your rifle to someone with the magnum version of the Safari - probably a .375 H&H - or look for a magnum length Interarms MkX or something similar to use.
The advantage, by the way, to using the shroud safety is that you acre actually taking the cocking piece (and also the firing pin) off the trigger sear, making accidental discharge impossible.
the trigger safeties instead just block the trigger from being pulled and in the case of a 3 position also stop the cocking piece from moving enough for the bolt to roatate, but it's not as safe as a shroud safety by any means. Not to mention the shroud safety looks way cooler and will make you the envy of mauser sporting rifle owners everywhere... lol.