What would you buy?

This may not meet your criteria however I would buy a clean pre model 70 375 H&H and be happy with life. When you have dependability, character and value, well like they say, you have about everything. Good luck in your pursuit...

Sure, buy it if the price is right. Just don't let it get water soaked for a week. Plastic is best for that. But I use wood since I am not going to rainy places.
Pre 64, would not be "new". A new production Model 70 would be. Assuming you want performance and not nostalgia.
I would build one, as I have done many times; anyone can buy a new rifle. Or depending on your skill; have someone do the metal and you do the wood...

Keep in mind that most pre 64s have at least 50 year old stocks. Ive never had warping with one of the many I have owned and hunted with, most custom rifles have nice pretty fantastic wood, much tends to be a couple of years old and it seems much of it warps with a little abuse. Picking your gun maker on custom rifle is a must..Ive seen plastic stocks melt in the trunk of a car or next to the tent fire, its a push IMO..Maintence is probably your best bet whichever way you go.

Winchester African.