Europe, your list of calibers is definitely a collection of classics. 9.3x74r would be pretty darn nice in a double rifle. I would love one of those, but I have no idea what I would use it for. I would have to go back to Africa for sure! And if I did that, kudu and buffalo would be the choice. I need to rob a bank!
What about the old American classics? .30-06 and .30-30 aren't really old to me. They were the popular cartridges of my childhood, so old classics have to predate that - at least if you ask me.
So, what about the American hyphenateds? We all know the .45-2.1" (aka the 70), though I trust most have never seen it in its classic loadings. Yet, it works every bit as well as ever. And the .45-2.4" (aka the 90) and the .45-2.875" (aka the 110) are fantastic cartridges.
The .44s are truly the lost classics. .44-77 especially. They were very popular but now only known a relative few gun cranks. The better known .45s are nearly identical and far easier to supply with brass and dies.
There were .40s of course. The .40-70 was fairly popular as was the .40-90 Sharps bottleneck, but they are almost as rare as the .44s today.
I suppose most think of the .38-55. Yet, like the .45-70, it is rarely loaded like it was intended. Still a great cartridge though. If you want a very light elk rifle - this would be a nice choice in a vintage lever action repeater. I doubt a single person here would consider it for that however.
Back then there were just as many short-lived flash-in-the-pans as there is today. The "express" cartridges with light bullets in long cases came and went with little more than a ripple on the shooting ponds. The Everlastings also sank quickly into obscurity. Some of them attempted to hang with the coming overwhelmingly oppressive smokeless, hyper-fast cartridges like the .30-30. I use a .38-72 which is certainly old, but not classic. Works okay but too much powder really. Makes a nice light elk rifle however - laser fast, flat-shootin'! You betchya!
The old cartridges and, especially, the old rifles are really pretty amazing and a lot of fun to research, track down, and capture and then prepare for duty with special marinades, just like your first elk. It is a lot like hunting before you even draw a tag.
If you see and old, interesting rifle, don't be afraid to give it a try. You might end up selling all your .308s and man-buns, etc. and revisit the old ways. It can really add to your experience. You also will not give up much of anything in the way of freezer filling in the end.