You're quite right: the accuracy of the rifles, even old ones, is still today quite astonishing. From the point of view of accuracy and serviceability, there is little or no reason for anyone owning one of those rifles (or a sporterized one) to give it up in favor of a newer one, to be quite honest. This was also one of the motivations behind me starting to customize the existing rifle rather than buying a new one.

I remember now that we've had discussions before: You then mentioned your correspondence with the late P.T. Kekkonen - quite a character he was! The Gunwriters Forum is still a marvelous source of accurate information and curio, although it is no longer updated of course.

The current gun laws are very lenient (the current law is currently under revision, though; after two very nasty and unfortunate school shootings) so the only restrictions one has with regards to hunting caliber is suitability and minimum power requirements. With sporting guns suitability for the intended use is the only criteria applied.
For moose, the .308 and .30-06 are still most popular, and if we add the 7,62x53R on top of that they cater for about 75% of all moose taken annually. The only smaller one really to have gained some ground is the 6,5x55 Swede, and a beautiful cartridge it is, too!