Interesting story and situation.
I think it is amazing that Savage would even attempt to refurbish an early TD rifle in 1986. But since they did, I'd be inclined to leave it alone. Savage likely did some tweaking of the barrel and forearm to make it fit and safe for use.
It may be possible to reverse the process, but, you'd need a barrel that fits (may not index properly), a compatible TD forearm, a skilled person to pull it together, but it will never be Gramp's original rifle anyway.
Sounds like Grampa's rifle was a 1899H TD. The letter would have stated that I think. ??
If you really want a rifle like Gramp's, go buy one. They are out there.
In the end, it is your rifle to do with as you please. Just don't screw it up.
Good luck.
