If the rifle is a collectible and is treated that way (not shot or hunted with, kept as an investment so as to increase it's value w/age),,then leave the old fossilized but ORIGINAL pad right where it is. It will, dispite it's granite like properties pay dividends when it come time to sell the rifle.

A replacement is a replacement. Investors in collectibles want originality.
Replacing a pad no matter if it's a repro that's 'just like the original' is just a reblue job 'that's just like the original.

Now if the rifle is a user and a shooter and a nice one at that. You hunt with it, target shoot and carry it carefully and just generally like the thing and have no real thoughts of staking your retirement on the value of it in ten years down the road,,,,then do yourself and you shoulder a favor and have old pad replaced.

I would recommend one of the repro pads that matches the original that's on the gun. It will better hold the value of the rifle than an aftermarket wizbang 'nokick special' and it will suit you just as well as the original did for the time you have owned it.
A pre-64 deserves at least that much...

JMO