The pre-64's were made by machining the receiver from bar stock. The current production M70's are forged. Pretty much everything about the current product rifles is at least as good or better than they ever were -- but what they are not are products of an immense amount of manual-machining, hand-checkering, hand-fitting, and human attention to detail that is best exemplified not just in pre-64's but actually best by pre-WWII Model 70's. If you just want function, the new rifles are as good or better in everyway. If you want a piece of history and a product of a bygone work ethic, they're just not the same.
Some years back, I inherited my grandfather's 5-digit (1942) M70 in 30.06. One of the so-called 'pre-War' M70s. The stock showed nicks and scratches, but it still had the factory-installed Lyman receiver aperture sight afixed to the left side. The front of the receiver bridge came factory pre-drill/tapped for a mount and, at some point, Gramps had a 'smith drill and tap the rear bridge.
But the slender factory stock, with steel buttplate, is definitely set up for iron-sighted shooting, a lost skill in an age of Metrosexuals who feel a heavy 10x scope might not yield enough magnification up at deer camp.
In fact the iron sights were dead-on at 100yds with just about any 150gn load I tried.
It was actually hard to find a factory '06 hunting load this rifle
didn't shoot well. Eventually I got a low-powered 1x-5x Leupy set up in the lowest mounts I could find, and then really started to play with it - factory ammo
and handloads.
The big surprise (to me) came when was running a box of Hornady's 'reduced load' 125gn SST ammo through it. I got consistent 5-shot MOA or better groups at 100yds.
This old bolt rifle is hands-down the most accurate .30-06 I've ever shot or owned.
The stuff they're churning out today couldn't hold a candle to it. The CZ CRF 550s - from my experience - are pretty good in the accuracy department, but unfortunately CZ phased those models out in favor of selling the PF crapola.
No school like Old School.