The OP has no choice on the sling swivel, if he wants to keep and use the stock. Those and the recoil pad are easy to replace and keep the originals for resale, if it comes to that. Not a big deal.
If it was my rig, I'd do what Hamrick suggested. Buy a stock to fit and mess with it to fit your needs and keep the original in the way back of the safe. That's what I've done with old rifles of sentimental value to preserve the original equipment. Also helps if plans change in the future and you or somebody else needs to sell it.
The old Finnbears that I've had the privilege to fondle had great fit, feel and balance. It is a beauty!
Only you can make the choice. Everybody has their own take on it. Go with what you want to do with your rifle.
